81897604 has 12 divisors (see below), whose sum is σ = 143483200. Its totient is φ = 40902408.

The previous prime is 81897589. The next prime is 81897611. The reversal of 81897604 is 40679818.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

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, 7464 + ... + 14815.

Almost surely, 2^81897604 is an apocalyptic number.

It is an amenable number.

81897604 is a deficient number, since it is larger than the sum of its proper divisors (61585596).

81897604 is a wasteful number, since it uses less digits than its factorization.

81897604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23202 (or 23200 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 81897604 is about 9049.7294987198. The cubic root of 81897604 is about 434.2672368598.

The spelling of 81897604 in words is "eighty-one million, eight hundred ninety-seven thousand, six hundred four".