81516554580 has 48 divisors (see below), whose sum is σ = 230462354304. Its totient is φ = 21526700160.

The previous prime is 81516554543. The next prime is 81516554597. The reversal of 81516554580 is 8545561518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6589011 + ... + 6601370.

It is an arithmetic number, because the mean of its divisors is an integer number (4801299048).

Almost surely, 2^81516554580 is an apocalyptic number.

It is an amenable number.

81516554580 is an abundant number, since it is smaller than the sum of its proper divisors (148945799724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81516554580 is a wasteful number, since it uses less digits than its factorization.

81516554580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13190496 (or 13190494 counting only the distinct ones).

The product of its (nonzero) digits is 960000, while the sum is 48.

The spelling of 81516554580 in words is "eighty-one billion, five hundred sixteen million, five hundred fifty-four thousand, five hundred eighty".