138500928 has 70 divisors (see below), whose sum is σ = 410575506. Its totient is φ = 46165248.

The previous prime is 138500903. The next prime is 138500933. The reversal of 138500928 is 829005831.

It can be written as a sum of positive squares in only one way, i.e., 100160064 + 38340864 = 10008^2 + 6192^2 .

It is a super-2 number, since 2×138500928² = 38365014113722368, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 138500892 and 138500901.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8175 + ... + 18542.

Almost surely, 2^138500928 is an apocalyptic number.

138500928 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138500928 is an abundant number, since it is smaller than the sum of its proper divisors (272074578).

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

138500928 is an equidigital number, since it uses as much as digits as its factorization.

138500928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26741 (or 26722 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 138500928 is about 11768.6417228158. The cubic root of 138500928 is about 517.3894407799.

The spelling of 138500928 in words is "one hundred thirty-eight million, five hundred thousand, nine hundred twenty-eight".