138880656 has 100 divisors (see below), whose sum is σ = 406323324. Its totient is φ = 45792000.

The previous prime is 138880627. The next prime is 138880661. The reversal of 138880656 is 656088831.

It can be written as a sum of positive squares in 2 ways, for example, as 116640000 + 22240656 = 10800^2 + 4716^2 .

It is a super-2 number, since 2×138880656² = 38575673221980672, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 130366 + ... + 131426.

Almost surely, 2^138880656 is an apocalyptic number.

138880656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138880656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203161662).

138880656 is an abundant number, since it is smaller than the sum of its proper divisors (267442668).

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

138880656 is a wasteful number, since it uses less digits than its factorization.

138880656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1182 (or 1167 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 138880656 is about 11784.7637227057. The cubic root of 138880656 is about 517.8618515235.

The spelling of 138880656 in words is "one hundred thirty-eight million, eight hundred eighty thousand, six hundred fifty-six".