123720638 has 8 divisors (see below), whose sum is σ = 189529632. Its totient is φ = 60544096.

The previous prime is 123720631. The next prime is 123720673. The reversal of 123720638 is 836027321.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123720631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 657995 + ... + 658182.

It is an arithmetic number, because the mean of its divisors is an integer number (23691204).

Almost surely, 2^123720638 is an apocalyptic number.

123720638 is a deficient number, since it is larger than the sum of its proper divisors (65808994).

123720638 is a wasteful number, since it uses less digits than its factorization.

123720638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316226.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 123720638 is about 11122.9779285945. The cubic root of 123720638 is about 498.2883310654.

Adding to 123720638 its reverse (836027321), we get a palindrome (959747959).

The spelling of 123720638 in words is "one hundred twenty-three million, seven hundred twenty thousand, six hundred thirty-eight".