138928524 has 72 divisors (see below), whose sum is σ = 378730800. Its totient is φ = 39521664.

The previous prime is 138928499. The next prime is 138928567. The reversal of 138928524 is 425829831.

It is a super-2 number, since 2×138928524² = 38602269561637152, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 204874 + ... + 205550.

It is an arithmetic number, because the mean of its divisors is an integer number (5260150).

Almost surely, 2^138928524 is an apocalyptic number.

138928524 is a gapful number since it is divisible by the number (14) 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 138928524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189365400).

138928524 is an abundant number, since it is smaller than the sum of its proper divisors (239802276).

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

138928524 is a wasteful number, since it uses less digits than its factorization.

138928524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1047 (or 1038 counting only the distinct ones).

The product of its digits is 138240, while the sum is 42.

The square root of 138928524 is about 11786.7944751743. The cubic root of 138928524 is about 517.9213418426.

The spelling of 138928524 in words is "one hundred thirty-eight million, nine hundred twenty-eight thousand, five hundred twenty-four".