81974692 has 12 divisors (see below), whose sum is σ = 143711820. Its totient is φ = 40914176.

The previous prime is 81974689. The next prime is 81974699. The reversal of 81974692 is 29647918.

It can be written as a sum of positive squares in 2 ways, for example, as 26977636 + 54997056 = 5194^2 + 7416^2 .

It is not an unprimeable number, because it can be changed into a prime (81974699) 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, 15733 + ... + 20284.

It is an arithmetic number, because the mean of its divisors is an integer number (11975985).

Almost surely, 2^81974692 is an apocalyptic number.

It is an amenable number.

81974692 is a deficient number, since it is larger than the sum of its proper divisors (61737128).

81974692 is a wasteful number, since it uses less digits than its factorization.

81974692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36590 (or 36588 counting only the distinct ones).

The product of its digits is 217728, while the sum is 46.

The square root of 81974692 is about 9053.9876297684. The cubic root of 81974692 is about 434.4034488001.

The spelling of 81974692 in words is "eighty-one million, nine hundred seventy-four thousand, six hundred ninety-two".