81342992 has 20 divisors (see below), whose sum is σ = 158846976. Its totient is φ = 40350240.

The previous prime is 81342991. The next prime is 81343021. The reversal of 81342992 is 29924318.

It is not an unprimeable number, because it can be changed into a prime (81342991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17984 + ... + 22047.

Almost surely, 2^81342992 is an apocalyptic number.

It is an amenable number.

81342992 is a deficient number, since it is larger than the sum of its proper divisors (77503984).

81342992 is a wasteful number, since it uses less digits than its factorization.

81342992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40166 (or 40160 counting only the distinct ones).

The product of its digits is 31104, while the sum is 38.

The square root of 81342992 is about 9019.0349816374. The cubic root of 81342992 is about 433.2847272240.

The spelling of 81342992 in words is "eighty-one million, three hundred forty-two thousand, nine hundred ninety-two".