138617722872 has 56 divisors (see below), whose sum is σ = 389684098440. Its totient is φ = 46205905680.

The previous prime is 138617722871. The next prime is 138617722909. The reversal of 138617722872 is 278227716831.

138617722872 is a `hidden beast` number, since 1 + 386 + 177 + 2 + 28 + 72 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138617722871) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 11878404 + ... + 11890067.

It is an arithmetic number, because the mean of its divisors is an integer number (6958644615).

Almost surely, 2^138617722872 is an apocalyptic number.

138617722872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

138617722872 is an abundant number, since it is smaller than the sum of its proper divisors (251066375568).

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

138617722872 is an equidigital number, since it uses as much as digits as its factorization.

138617722872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23768495 (or 23768476 counting only the distinct ones).

The product of its digits is 3161088, while the sum is 54.

The spelling of 138617722872 in words is "one hundred thirty-eight billion, six hundred seventeen million, seven hundred twenty-two thousand, eight hundred seventy-two".