72431591 has 4 divisors (see below), whose sum is σ = 76243800. Its totient is φ = 68619384.

The previous prime is 72431587. The next prime is 72431609. The reversal of 72431591 is 19513427.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19513427 = 71 ⋅274837.

It is a cyclic number.

It is not a de Polignac number, because 72431591 - 2² = 72431587 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 (72431501) 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, 1906076 + ... + 1906113.

It is an arithmetic number, because the mean of its divisors is an integer number (19060950).

Almost surely, 2^72431591 is an apocalyptic number.

72431591 is a deficient number, since it is larger than the sum of its proper divisors (3812209).

72431591 is a wasteful number, since it uses less digits than its factorization.

72431591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3812208.

The product of its digits is 7560, while the sum is 32.

The square root of 72431591 is about 8510.6751201065. The cubic root of 72431591 is about 416.8463549957.

The spelling of 72431591 in words is "seventy-two million, four hundred thirty-one thousand, five hundred ninety-one".