138491973 has 24 divisors (see below), whose sum is σ = 211550976. Its totient is φ = 87163200.

The previous prime is 138491963. The next prime is 138491981. The reversal of 138491973 is 379194831.

It is not a de Polignac number, because 138491973 - 2⁴ = 138491957 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138491933) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5386 + ... + 17492.

It is an arithmetic number, because the mean of its divisors is an integer number (8814624).

Almost surely, 2^138491973 is an apocalyptic number.

It is an amenable number.

138491973 is a deficient number, since it is larger than the sum of its proper divisors (73059003).

138491973 is a wasteful number, since it uses less digits than its factorization.

138491973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12185 (or 12182 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 138491973 is about 11768.2612564474. The cubic root of 138491973 is about 517.3782896578.

The spelling of 138491973 in words is "one hundred thirty-eight million, four hundred ninety-one thousand, nine hundred seventy-three".