81604670872490 has 16 divisors (see below), whose sum is σ = 146915364616200. Its totient is φ = 32635877894400.

The previous prime is 81604670872471. The next prime is 81604670872507. The reversal of 81604670872490 is 9427807640618.

It can be written as a sum of positive squares in 4 ways, for example, as 51689010903049 + 29915659969441 = 7189507^2 + 5469521^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 748749611 + ... + 748858590.

Almost surely, 2^{81604670872490} is an apocalyptic number.

81604670872490 is a deficient number, since it is larger than the sum of its proper divisors (65310693743710).

81604670872490 is a wasteful number, since it uses less digits than its factorization.

81604670872490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1497613657.

The product of its (nonzero) digits is 32514048, while the sum is 62.

The spelling of 81604670872490 in words is "eighty-one trillion, six hundred four billion, six hundred seventy million, eight hundred seventy-two thousand, four hundred ninety".