81957472 has 24 divisors (see below), whose sum is σ = 164789856. Its totient is φ = 40106112.

The previous prime is 81957467. The next prime is 81957503. The reversal of 81957472 is 27475918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25743 + ... + 28750.

It is an arithmetic number, because the mean of its divisors is an integer number (6866244).

Almost surely, 2^81957472 is an apocalyptic number.

It is an amenable number.

81957472 is an abundant number, since it is smaller than the sum of its proper divisors (82832384).

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

81957472 is a wasteful number, since it uses less digits than its factorization.

81957472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54550 (or 54542 counting only the distinct ones).

The product of its digits is 141120, while the sum is 43.

The square root of 81957472 is about 9053.0366176217. The cubic root of 81957472 is about 434.3730290406.

The spelling of 81957472 in words is "eighty-one million, nine hundred fifty-seven thousand, four hundred seventy-two".