81628304 has 20 divisors (see below), whose sum is σ = 158910960. Its totient is φ = 40619040.

The previous prime is 81628303. The next prime is 81628307. The reversal of 81628304 is 40382618.

It is not an unprimeable number, because it can be changed into a prime (81628303) 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, 8714 + ... + 15465.

It is an arithmetic number, because the mean of its divisors is an integer number (7945548).

Almost surely, 2^81628304 is an apocalyptic number.

It is an amenable number.

81628304 is a deficient number, since it is larger than the sum of its proper divisors (77282656).

81628304 is a wasteful number, since it uses less digits than its factorization.

81628304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24398 (or 24392 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 81628304 is about 9034.8383494117. The cubic root of 81628304 is about 433.7907207352.

The spelling of 81628304 in words is "eighty-one million, six hundred twenty-eight thousand, three hundred four".