138868904 has 32 divisors (see below), whose sum is σ = 266823720. Its totient is φ = 67731456.

The previous prime is 138868901. The next prime is 138868909. The reversal of 138868904 is 409868831.

It can be written as a sum of positive squares in 4 ways, for example, as 136936804 + 1932100 = 11702^2 + 1390^2 .

It is a super-2 number, since 2×138868904² = 38569144996322432, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138868901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80984 + ... + 82680.

Almost surely, 2^138868904 is an apocalyptic number.

It is an amenable number.

138868904 is a deficient number, since it is larger than the sum of its proper divisors (127954816).

138868904 is a wasteful number, since it uses less digits than its factorization.

138868904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1949 (or 1945 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 47.

The square root of 138868904 is about 11784.2651022455. The cubic root of 138868904 is about 517.8472440556.

The spelling of 138868904 in words is "one hundred thirty-eight million, eight hundred sixty-eight thousand, nine hundred four".