72986391 has 24 divisors (see below), whose sum is σ = 111371520. Its totient is φ = 45931536.

The previous prime is 72986387. The next prime is 72986393. The reversal of 72986391 is 19368927.

72986391 is a `hidden beast` number, since 7 + 2 + 9 + 8 + 639 + 1 = 666.

It is not a de Polignac number, because 72986391 - 2² = 72986387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72986393) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62176 + ... + 63338.

It is an arithmetic number, because the mean of its divisors is an integer number (4640480).

Almost surely, 2^72986391 is an apocalyptic number.

72986391 is a deficient number, since it is larger than the sum of its proper divisors (38385129).

72986391 is a wasteful number, since it uses less digits than its factorization.

72986391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1555 (or 1552 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 72986391 is about 8543.2073017105. The cubic root of 72986391 is about 417.9079469615.

It can be divided in two parts, 7298 and 6391, that added together give a square (13689 = 117²).

The spelling of 72986391 in words is "seventy-two million, nine hundred eighty-six thousand, three hundred ninety-one".