81924004 has 12 divisors (see below), whose sum is σ = 144169200. Its totient is φ = 40732808.

The previous prime is 81924001. The next prime is 81924047. The reversal of 81924004 is 40042918.

It is not an unprimeable number, because it can be changed into a prime (81924001) 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, 56494 + ... + 57925.

It is an arithmetic number, because the mean of its divisors is an integer number (12014100).

Almost surely, 2^81924004 is an apocalyptic number.

It is an amenable number.

81924004 is a deficient number, since it is larger than the sum of its proper divisors (62245196).

81924004 is a wasteful number, since it uses less digits than its factorization.

81924004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114602 (or 114600 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 81924004 is about 9051.1879883251. The cubic root of 81924004 is about 434.3138944046.

The spelling of 81924004 in words is "eighty-one million, nine hundred twenty-four thousand, four".