138251408 has 10 divisors (see below), whose sum is σ = 267862134. Its totient is φ = 69125696.

The previous prime is 138251387. The next prime is 138251411. The reversal of 138251408 is 804152831.

138251408 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 76597504 + 61653904 = 8752^2 + 7852^2 .

It is a super-2 number, since 2×138251408² = 38226903627964928, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4320341 + ... + 4320372.

Almost surely, 2^138251408 is an apocalyptic number.

It is an amenable number.

138251408 is a deficient number, since it is larger than the sum of its proper divisors (129610726).

138251408 is an equidigital number, since it uses as much as digits as its factorization.

138251408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8640721 (or 8640715 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 138251408 is about 11758.0358904028. The cubic root of 138251408 is about 517.0785484751.

The spelling of 138251408 in words is "one hundred thirty-eight million, two hundred fifty-one thousand, four hundred eight".