72747391 has 4 divisors (see below), whose sum is σ = 72764784. Its totient is φ = 72730000.

The previous prime is 72747377. The next prime is 72747397. The reversal of 72747391 is 19374727.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72747391 - 2⁷ = 72747263 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 (72747397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1806 + ... + 12196.

It is an arithmetic number, because the mean of its divisors is an integer number (18191196).

Almost surely, 2^72747391 is an apocalyptic number.

72747391 is a deficient number, since it is larger than the sum of its proper divisors (17393).

72747391 is a wasteful number, since it uses less digits than its factorization.

72747391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17392.

The product of its digits is 74088, while the sum is 40.

The square root of 72747391 is about 8529.2081109561. The cubic root of 72747391 is about 417.4512900491.

The spelling of 72747391 in words is "seventy-two million, seven hundred forty-seven thousand, three hundred ninety-one".