72617009138 has 4 divisors (see below), whose sum is σ = 108925513710. Its totient is φ = 36308504568.

The previous prime is 72617009117. The next prime is 72617009147. The reversal of 72617009138 is 83190071627.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83190071627 = 13 ⋅6399236279.

It can be written as a sum of positive squares in only one way, i.e., 67924348129 + 4692661009 = 260623^2 + 68503^2 .

It is a super-2 number, since 2×72617009138² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18154252283 + ... + 18154252286.

Almost surely, 2^72617009138 is an apocalyptic number.

72617009138 is a deficient number, since it is larger than the sum of its proper divisors (36308504572).

72617009138 is a wasteful number, since it uses less digits than its factorization.

72617009138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36308504571.

The product of its (nonzero) digits is 127008, while the sum is 44.

The spelling of 72617009138 in words is "seventy-two billion, six hundred seventeen million, nine thousand, one hundred thirty-eight".