138940644 has 12 divisors (see below), whose sum is σ = 324194864. Its totient is φ = 46313544.

The previous prime is 138940639. The next prime is 138940679. The reversal of 138940644 is 446049831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5789182 + ... + 5789205.

Almost surely, 2^138940644 is an apocalyptic number.

It is an amenable number.

138940644 is an abundant number, since it is smaller than the sum of its proper divisors (185254220).

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

138940644 is a wasteful number, since it uses less digits than its factorization.

138940644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11578394 (or 11578392 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 138940644 is about 11787.3085986581. The cubic root of 138940644 is about 517.9364024026.

The spelling of 138940644 in words is "one hundred thirty-eight million, nine hundred forty thousand, six hundred forty-four".