138625056 has 72 divisors (see below), whose sum is σ = 406957824. Its totient is φ = 44714880.

The previous prime is 138625049. The next prime is 138625061. The reversal of 138625056 is 650526831.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 138625056.

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, 1165 + ... + 16691.

It is an arithmetic number, because the mean of its divisors is an integer number (5652192).

Almost surely, 2^138625056 is an apocalyptic number.

138625056 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 138625056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203478912).

138625056 is an abundant number, since it is smaller than the sum of its proper divisors (268332768).

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

138625056 is a wasteful number, since it uses less digits than its factorization.

138625056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15574 (or 15563 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 138625056 is about 11773.9142174555. The cubic root of 138625056 is about 517.5439604187.

The spelling of 138625056 in words is "one hundred thirty-eight million, six hundred twenty-five thousand, fifty-six".