81316492 has 6 divisors (see below), whose sum is σ = 142303868. Its totient is φ = 40658244.

The previous prime is 81316481. The next prime is 81316567. The reversal of 81316492 is 29461318.

It is a super-2 number, since 2×81316492² = 13224743742372128, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10164558 + ... + 10164565.

Almost surely, 2^81316492 is an apocalyptic number.

It is an amenable number.

81316492 is a deficient number, since it is larger than the sum of its proper divisors (60987376).

81316492 is a wasteful number, since it uses less digits than its factorization.

81316492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20329127 (or 20329125 counting only the distinct ones).

The product of its digits is 10368, while the sum is 34.

The square root of 81316492 is about 9017.5657469186. The cubic root of 81316492 is about 433.2376701386.

The spelling of 81316492 in words is "eighty-one million, three hundred sixteen thousand, four hundred ninety-two".