81972232 has 32 divisors (see below), whose sum is σ = 171309600. Its totient is φ = 36543744.

The previous prime is 81972229. The next prime is 81972239. The reversal of 81972232 is 23227918.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (81972239) 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, 13278 + ... + 18445.

It is an arithmetic number, because the mean of its divisors is an integer number (5353425).

Almost surely, 2^81972232 is an apocalyptic number.

It is an amenable number.

81972232 is an abundant number, since it is smaller than the sum of its proper divisors (89337368).

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

81972232 is a wasteful number, since it uses less digits than its factorization.

81972232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31765 (or 31761 counting only the distinct ones).

The product of its digits is 12096, while the sum is 34.

The square root of 81972232 is about 9053.8517770063. The cubic root of 81972232 is about 434.3991033810.

The spelling of 81972232 in words is "eighty-one million, nine hundred seventy-two thousand, two hundred thirty-two".