138979656 has 48 divisors (see below), whose sum is σ = 379392000. Its totient is φ = 45958752.

The previous prime is 138979649. The next prime is 138979681. The reversal of 138979656 is 656979831.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1545 + ... + 16743.

It is an arithmetic number, because the mean of its divisors is an integer number (7904000).

Almost surely, 2^138979656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138979656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189696000).

138979656 is an abundant number, since it is smaller than the sum of its proper divisors (240412344).

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

138979656 is a wasteful number, since it uses less digits than its factorization.

138979656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15338 (or 15331 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 54.

The square root of 138979656 is about 11788.9633132010. The cubic root of 138979656 is about 517.9848735663.

The spelling of 138979656 in words is "one hundred thirty-eight million, nine hundred seventy-nine thousand, six hundred fifty-six".