81624460 has 24 divisors (see below), whose sum is σ = 171598896. Its totient is φ = 32614080.

The previous prime is 81624443. The next prime is 81624461. The reversal of 81624460 is 6442618.

81624460 is digitally balanced in base 9, because in such base it contains all the possibile digits an equal number of times.

81624460 is strictly pandigital in base 9.

It is not an unprimeable number, because it can be changed into a prime (81624461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24070 + ... + 27250.

It is an arithmetic number, because the mean of its divisors is an integer number (7149954).

Almost surely, 2^81624460 is an apocalyptic number.

It is an amenable number.

81624460 is an abundant number, since it is smaller than the sum of its proper divisors (89974436).

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

81624460 is a wasteful number, since it uses less digits than its factorization.

81624460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4473 (or 4471 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 81624460 is about 9034.6256148221. The cubic root of 81624460 is about 433.7839113418.

The spelling of 81624460 in words is "eighty-one million, six hundred twenty-four thousand, four hundred sixty".