138508644 has 48 divisors (see below), whose sum is σ = 328099968. Its totient is φ = 45474048.

The previous prime is 138508637. The next prime is 138508661. The reversal of 138508644 is 446805831.

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 in 15 ways as a sum of consecutive naturals, for example, 284169 + ... + 284655.

It is an arithmetic number, because the mean of its divisors is an integer number (6835416).

Almost surely, 2^138508644 is an apocalyptic number.

It is an amenable number.

138508644 is an abundant number, since it is smaller than the sum of its proper divisors (189591324).

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

138508644 is a wasteful number, since it uses less digits than its factorization.

138508644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804 (or 802 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 39.

The square root of 138508644 is about 11768.9695385790. The cubic root of 138508644 is about 517.3990486645.

The spelling of 138508644 in words is "one hundred thirty-eight million, five hundred eight thousand, six hundred forty-four".