81556445334 has 32 divisors (see below), whose sum is σ = 200754328320. Its totient is φ = 21509392032.

The previous prime is 81556445309. The next prime is 81556445431. The reversal of 81556445334 is 43354465518.

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, 74684844 + ... + 74685935.

It is an arithmetic number, because the mean of its divisors is an integer number (6273572760).

Almost surely, 2^81556445334 is an apocalyptic number.

81556445334 is an abundant number, since it is smaller than the sum of its proper divisors (119197882986).

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

81556445334 is a wasteful number, since it uses less digits than its factorization.

81556445334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149370804.

The product of its digits is 3456000, while the sum is 48.

The spelling of 81556445334 in words is "eighty-one billion, five hundred fifty-six million, four hundred forty-five thousand, three hundred thirty-four".