138631656 has 32 divisors (see below), whose sum is σ = 354641760. Its totient is φ = 45135552.

The previous prime is 138631639. The next prime is 138631673. The reversal of 138631656 is 656136831.

It is an interprime number because it is at equal distance from previous prime (138631639) and next prime (138631673).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66135 + ... + 68198.

It is an arithmetic number, because the mean of its divisors is an integer number (11082555).

Almost surely, 2^138631656 is an apocalyptic number.

It is an amenable number.

138631656 is an abundant number, since it is smaller than the sum of its proper divisors (216010104).

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

138631656 is a wasteful number, since it uses less digits than its factorization.

138631656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134385 (or 134381 counting only the distinct ones).

The product of its digits is 77760, while the sum is 39.

The square root of 138631656 is about 11774.1944947415. The cubic root of 138631656 is about 517.5521737871.

The spelling of 138631656 in words is "one hundred thirty-eight million, six hundred thirty-one thousand, six hundred fifty-six".