72731213 has 4 divisors (see below), whose sum is σ = 72778080. Its totient is φ = 72684348.

The previous prime is 72731209. The next prime is 72731273. The reversal of 72731213 is 31213727.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72731213 - 2² = 72731209 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 (72731203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21023 + ... + 24236.

It is an arithmetic number, because the mean of its divisors is an integer number (18194520).

Almost surely, 2^72731213 is an apocalyptic number.

It is an amenable number.

72731213 is a deficient number, since it is larger than the sum of its proper divisors (46867).

72731213 is a wasteful number, since it uses less digits than its factorization.

72731213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46866.

The product of its digits is 1764, while the sum is 26.

The square root of 72731213 is about 8528.2596700616. The cubic root of 72731213 is about 417.4203426498.

The spelling of 72731213 in words is "seventy-two million, seven hundred thirty-one thousand, two hundred thirteen".