81920272 has 40 divisors (see below), whose sum is σ = 181980416. Its totient is φ = 34995456.

The previous prime is 81920243. The next prime is 81920281. The reversal of 81920272 is 27202918.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40108 + ... + 42100.

Almost surely, 2^81920272 is an apocalyptic number.

It is an amenable number.

81920272 is an abundant number, since it is smaller than the sum of its proper divisors (100060144).

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

81920272 is a wasteful number, since it uses less digits than its factorization.

81920272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2375 (or 2369 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 81920272 is about 9050.9818251944. The cubic root of 81920272 is about 434.3072993328.

The spelling of 81920272 in words is "eighty-one million, nine hundred twenty thousand, two hundred seventy-two".