You can call me at whichever number.
どちらの番号に電話してもいいよ。
→"call me at"は”call me on"としても大丈夫です。
You can reach me at whichever number.
どちらの番号でも連絡つくよ。
→意外と便利なのが"reach"。たどり着くというニュアンスですが、
電話だけではなくて荷物などが届くというときも、幅広く使えます！
You can contact me at either one of these numbers.
Feel free to call me on either of my cell phones.
In American English, either one of these sentences are acceptable so that the person listening understands that they are able to communicate with you at either number. The phrase "contact me" is a little more formal than "call me", and can be used when you're talking with a co-worker, or in a professional setting.
I hope that this helps. :)
Pleasew get hold of me through either of my phones
Either of my phone numbers may be used to reach me.
To get hold of someone/to reach someone (by phone) are commonly used expressions.
EX. "I rang Clive 5 times but couldn't get hold of him."
EX. "I tried reaching Clive by phone but he was always unavailable."
To get hold of someone/to reach someone (by phone)は、よく使う表現です。
例：
"I rang Clive 5 times but couldn't get hold of him."
クライブに5回も電話したけど、繋がらなかった。
例：
"I tried reaching Clive by phone but he was always unavailable."
クライブに電話しようとしたけど、繋がらなかった。
"You can call me on either of these numbers. ": By saying this it would mean that you are always available on those numbers.
"I am reachable on either of these numbers." To tell someone that you are reachable means that they can contact you on either of those numbers.
I hope that helps.
"You can call me on either of these numbers. "
どちらの番号に電話してもいいよ。
これは、あなたがどちらの番号でもいつも都合がつくということを表します。
"I am reachable on either of these numbers."
どちらの番号でもつながります。
reachableとは、連絡がつながるという意味です。
Feel free to contact me on either of my mobile numbers.
You can reach me on both of my mobiles.
We make use of the word available to indicate that we are free and reachable on the following numbers.The second sentence 'Feel free to contact me on either of my mobile numbers.' is more friendly and polite. The last examples is a more casual and straight to the point way to express oneself.
この場合、両方の番号に繋がるという意味で、 free やreachable という言葉を使うことができます。
二つ目の例の、'Feel free to contact me on either of my mobile numbers.'（どちらの番号でも気軽に連絡してください）はもっとフレンドリーで丁寧な表現です。
最後の例は、もっとカジュアルで、ストレートに伝えたいことを伝えるフレーズです。
If you have 2 of something and can use both of them then you would say you can 'use either one'
When talking about mobile phones you would refer to them using your phone 'number' so can say 'you can call either number'
何かが二つあってどちらを使ってもいいなら、'use either one' と言えます。
携帯電話は電話番号によって識別されますね。ですから、'you can call either number'（どちらの番号にかけても大丈夫です）と言えます。
I have two numbers and I will be available on both.
It doesn't matter which number you call me on.
You can call either number.
Either one of these statements will be effective. In the first one 'I have two numbers and I will be available on both' you are implying that if they called, you would answer both.
The other two statements let the person know directly that they can call on both.
これらの文どれも使えます。
一つ目の例の
'I have two numbers and I will be available on both'（二つ番号があって、どちらにかけてもらっても構いません）
は、「どちらの番号に電話をかけてもらっても私は出ます」というニュアンスです。
あとの二つの例では、ストレートに「どちらに電話をかけても構わない」と伝えています。
日本 
アメリカ合衆国 
イギリス 
南アフリカ 
