81624937 has 12 divisors (see below), whose sum is σ = 85790016. Its totient is φ = 77643440.

The previous prime is 81624919. The next prime is 81624967. The reversal of 81624937 is 73942618.

It is not a de Polignac number, because 81624937 - 2¹⁵ = 81592169 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81624937.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81624967) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59028 + ... + 60394.

It is an arithmetic number, because the mean of its divisors is an integer number (7149168).

Almost surely, 2^81624937 is an apocalyptic number.

It is an amenable number.

81624937 is a deficient number, since it is larger than the sum of its proper divisors (4165079).

81624937 is a wasteful number, since it uses less digits than its factorization.

81624937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1496 (or 1467 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 81624937 is about 9034.6520132211. The cubic root of 81624937 is about 433.7847563276.

The spelling of 81624937 in words is "eighty-one million, six hundred twenty-four thousand, nine hundred thirty-seven".