81936576 has 56 divisors (see below), whose sum is σ = 240883440. Its totient is φ = 27311616.

The previous prime is 81936563. The next prime is 81936623. The reversal of 81936576 is 67563918.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21981 + ... + 25436.

It is an arithmetic number, because the mean of its divisors is an integer number (4301490).

Almost surely, 2^81936576 is an apocalyptic number.

It is an amenable number.

81936576 is an abundant number, since it is smaller than the sum of its proper divisors (158946864).

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

81936576 is a wasteful number, since it uses less digits than its factorization.

81936576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47438 (or 47422 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 81936576 is about 9051.8824561524. The cubic root of 81936576 is about 434.3361097698.

The spelling of 81936576 in words is "eighty-one million, nine hundred thirty-six thousand, five hundred seventy-six".