72639993 has 16 divisors (see below), whose sum is σ = 98629376. Its totient is φ = 47543760.

The previous prime is 72639979. The next prime is 72640019. The reversal of 72639993 is 39993627.

It is not a de Polignac number, because 72639993 - 2⁴ = 72639977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72639923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104778 + ... + 105468.

It is an arithmetic number, because the mean of its divisors is an integer number (6164336).

Almost surely, 2^72639993 is an apocalyptic number.

It is an amenable number.

72639993 is a deficient number, since it is larger than the sum of its proper divisors (25989383).

72639993 is a wasteful number, since it uses less digits than its factorization.

72639993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1284.

The product of its digits is 551124, while the sum is 48.

The square root of 72639993 is about 8522.9098904071. The cubic root of 72639993 is about 417.2457591295.

The spelling of 72639993 in words is "seventy-two million, six hundred thirty-nine thousand, nine hundred ninety-three".