138904 has 16 divisors (see below), whose sum is σ = 264600. Its totient is φ = 68352.

The previous prime is 138899. The next prime is 138917. The reversal of 138904 is 409831.

It is a plaindrome in base 14.

It is a congruent number.

It is an unprimeable number.

138904 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 687 + ... + 865.

2¹³⁸⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

138904 is a deficient number, since it is larger than the sum of its proper divisors (125696).

138904 is a wasteful number, since it uses less digits than its factorization.

138904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 138904 is about 372.6982693815. The cubic root of 138904 is about 51.7890865139.

The spelling of 138904 in words is "one hundred thirty-eight thousand, nine hundred four".