81683928 has 48 divisors (see below), whose sum is σ = 222378000. Its totient is φ = 27086400.

The previous prime is 81683911. The next prime is 81683939. The reversal of 81683928 is 82938618.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11478 + ... + 17178.

It is an arithmetic number, because the mean of its divisors is an integer number (4632875).

Almost surely, 2^81683928 is an apocalyptic number.

It is an amenable number.

81683928 is an abundant number, since it is smaller than the sum of its proper divisors (140694072).

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

81683928 is a wasteful number, since it uses less digits than its factorization.

81683928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5912 (or 5905 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 81683928 is about 9037.9161314985. The cubic root of 81683928 is about 433.8892310769.

The spelling of 81683928 in words is "eighty-one million, six hundred eighty-three thousand, nine hundred twenty-eight".