123642015138 has 48 divisors (see below), whose sum is σ = 291873152160. Its totient is φ = 38789646912.

The previous prime is 123642015109. The next prime is 123642015151. The reversal of 123642015138 is 831510246321.

123642015138 is a `hidden beast` number, since 1 + 2 + 3 + 642 + 0 + 1 + 5 + 1 + 3 + 8 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3945756 + ... + 3976967.

It is an arithmetic number, because the mean of its divisors is an integer number (6080690670).

Almost surely, 2^123642015138 is an apocalyptic number.

123642015138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

123642015138 is an abundant number, since it is smaller than the sum of its proper divisors (168231137022).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123642015138 is a wasteful number, since it uses less digits than its factorization.

123642015138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7922768 (or 7922745 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 123642015138 in words is "one hundred twenty-three billion, six hundred forty-two million, fifteen thousand, one hundred thirty-eight".