81979432 has 32 divisors (see below), whose sum is σ = 156451680. Its totient is φ = 40265280.

The previous prime is 81979411. The next prime is 81979439. The reversal of 81979432 is 23497918.

It is not an unprimeable number, because it can be changed into a prime (81979439) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 219598 + ... + 219970.

It is an arithmetic number, because the mean of its divisors is an integer number (4889115).

Almost surely, 2^81979432 is an apocalyptic number.

It is an amenable number.

81979432 is a deficient number, since it is larger than the sum of its proper divisors (74472248).

81979432 is a wasteful number, since it uses less digits than its factorization.

81979432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 793 (or 789 counting only the distinct ones).

The product of its digits is 108864, while the sum is 43.

The square root of 81979432 is about 9054.2493890990. The cubic root of 81979432 is about 434.4118214356.

The spelling of 81979432 in words is "eighty-one million, nine hundred seventy-nine thousand, four hundred thirty-two".