138815973 has 6 divisors (see below), whose sum is σ = 200511974. Its totient is φ = 92543976.

The previous prime is 138815933. The next prime is 138815987. The reversal of 138815973 is 379518831.

It can be written as a sum of positive squares in only one way, i.e., 123276609 + 15539364 = 11103^2 + 3942^2 .

It is not a de Polignac number, because 138815973 - 2⁸ = 138815717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138815933) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7711990 + ... + 7712007.

Almost surely, 2^138815973 is an apocalyptic number.

It is an amenable number.

138815973 is a deficient number, since it is larger than the sum of its proper divisors (61696001).

138815973 is a wasteful number, since it uses less digits than its factorization.

138815973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15424003 (or 15424000 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 138815973 is about 11782.0190544745. The cubic root of 138815973 is about 517.7814418135.

The spelling of 138815973 in words is "one hundred thirty-eight million, eight hundred fifteen thousand, nine hundred seventy-three".