81920004 has 48 divisors (see below), whose sum is σ = 194830272. Its totient is φ = 26785792.

The previous prime is 81919993. The next prime is 81920021. The reversal of 81920004 is 40002918.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 231892 + ... + 232244.

It is an arithmetic number, because the mean of its divisors is an integer number (4058964).

Almost surely, 2^81920004 is an apocalyptic number.

It is an amenable number.

81920004 is an abundant number, since it is smaller than the sum of its proper divisors (112910268).

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

81920004 is a wasteful number, since it uses less digits than its factorization.

81920004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 81920004 is about 9050.9670201587. The cubic root of 81920004 is about 434.3068257240.

It can be divided in two parts, 8192000 and 4, that multiplied together give a cube (32768000 = 320³).

The spelling of 81920004 in words is "eighty-one million, nine hundred twenty thousand, four".