138972690 has 48 divisors (see below), whose sum is σ = 372992256. Its totient is φ = 35863200.

The previous prime is 138972683. The next prime is 138972697. The reversal of 138972690 is 96279831.

138972690 is a `hidden beast` number, since 1 + 389 + 7 + 269 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (138972683) and next prime (138972697).

It is a super-2 number, since 2×138972690² = 38626817131672200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (138972697) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22116 + ... + 27695.

It is an arithmetic number, because the mean of its divisors is an integer number (7770672).

Almost surely, 2^138972690 is an apocalyptic number.

138972690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138972690 is an abundant number, since it is smaller than the sum of its proper divisors (234019566).

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

138972690 is a wasteful number, since it uses less digits than its factorization.

138972690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49855 (or 49852 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 138972690 is about 11788.6678636731. The cubic root of 138972690 is about 517.9762191992.

The spelling of 138972690 in words is "one hundred thirty-eight million, nine hundred seventy-two thousand, six hundred ninety".