81624940 has 24 divisors (see below), whose sum is σ = 171706752. Its totient is φ = 32593920.

The previous prime is 81624919. The next prime is 81624967. The reversal of 81624940 is 4942618.

It is a junction number, because it is equal to n+sod(n) for n = 81624896 and 81624905.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9637 + ... + 16003.

It is an arithmetic number, because the mean of its divisors is an integer number (7154448).

Almost surely, 2^81624940 is an apocalyptic number.

It is an amenable number.

81624940 is an abundant number, since it is smaller than the sum of its proper divisors (90081812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81624940 is a wasteful number, since it uses less digits than its factorization.

81624940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7017 (or 7015 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 81624940 is about 9034.6521792485. The cubic root of 81624940 is about 433.7847616420.

The spelling of 81624940 in words is "eighty-one million, six hundred twenty-four thousand, nine hundred forty".