81497764 has 12 divisors (see below), whose sum is σ = 150127600. Its totient is φ = 38604168.

The previous prime is 81497761. The next prime is 81497789. The reversal of 81497764 is 46779418.

It is not an unprimeable number, because it can be changed into a prime (81497761) 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, 536094 + ... + 536245.

Almost surely, 2^81497764 is an apocalyptic number.

It is an amenable number.

81497764 is a deficient number, since it is larger than the sum of its proper divisors (68629836).

81497764 is a wasteful number, since it uses less digits than its factorization.

81497764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072362 (or 1072360 counting only the distinct ones).

The product of its digits is 338688, while the sum is 46.

The square root of 81497764 is about 9027.6112011982. The cubic root of 81497764 is about 433.5593579573.

The spelling of 81497764 in words is "eighty-one million, four hundred ninety-seven thousand, seven hundred sixty-four".