81920492 has 12 divisors (see below), whose sum is σ = 143873016. Its totient is φ = 40813920.

The previous prime is 81920459. The next prime is 81920513. The reversal of 81920492 is 29402918.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35318 + ... + 37565.

It is an arithmetic number, because the mean of its divisors is an integer number (11989418).

Almost surely, 2^81920492 is an apocalyptic number.

It is an amenable number.

81920492 is a deficient number, since it is larger than the sum of its proper divisors (61952524).

81920492 is a wasteful number, since it uses less digits than its factorization.

81920492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73168 (or 73166 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 81920492 is about 9050.9939785639. The cubic root of 81920492 is about 434.3076881153.

The spelling of 81920492 in words is "eighty-one million, nine hundred twenty thousand, four hundred ninety-two".