81889572 has 24 divisors (see below), whose sum is σ = 194209792. Its totient is φ = 26848800.

The previous prime is 81889567. The next prime is 81889573. The reversal of 81889572 is 27598818.

It is not an unprimeable number, because it can be changed into a prime (81889573) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55204 + ... + 56667.

Almost surely, 2^81889572 is an apocalyptic number.

It is an amenable number.

81889572 is an abundant number, since it is smaller than the sum of its proper divisors (112320220).

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

81889572 is a wasteful number, since it uses less digits than its factorization.

81889572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111939 (or 111937 counting only the distinct ones).

The product of its digits is 322560, while the sum is 48.

The square root of 81889572 is about 9049.2857176685. The cubic root of 81889572 is about 434.2530396659.

The spelling of 81889572 in words is "eighty-one million, eight hundred eighty-nine thousand, five hundred seventy-two".