81057432 has 16 divisors (see below), whose sum is σ = 202643640. Its totient is φ = 27019136.

The previous prime is 81057421. The next prime is 81057437. The reversal of 81057432 is 23475018.

It is a self number, because there is not a number n which added to its sum of digits gives 81057432.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81057437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1688673 + ... + 1688720.

Almost surely, 2^81057432 is an apocalyptic number.

It is an amenable number.

81057432 is an abundant number, since it is smaller than the sum of its proper divisors (121586208).

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

81057432 is a wasteful number, since it uses less digits than its factorization.

81057432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3377402 (or 3377398 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 81057432 is about 9003.1901012919. The cubic root of 81057432 is about 432.7771077690. Note that the first 3 decimals are identical.

The spelling of 81057432 in words is "eighty-one million, fifty-seven thousand, four hundred thirty-two".