81610529764 has 6 divisors (see below), whose sum is σ = 142818427094. Its totient is φ = 40805264880.

The previous prime is 81610529603. The next prime is 81610529789. The reversal of 81610529764 is 46792501618.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 76374849600 + 5235680164 = 276360^2 + 72358^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10201316217 + ... + 10201316224.

Almost surely, 2^81610529764 is an apocalyptic number.

It is an amenable number.

81610529764 is a deficient number, since it is larger than the sum of its proper divisors (61207897330).

81610529764 is a wasteful number, since it uses less digits than its factorization.

81610529764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20402632445 (or 20402632443 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 49.

The spelling of 81610529764 in words is "eighty-one billion, six hundred ten million, five hundred twenty-nine thousand, seven hundred sixty-four".