81297195916 has 12 divisors (see below), whose sum is σ = 148455749232. Its totient is φ = 38881267568.

The previous prime is 81297195911. The next prime is 81297195919. The reversal of 81297195916 is 61959179218.

It is not an unprimeable number, because it can be changed into a prime (81297195911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441832495 + ... + 441832678.

It is an arithmetic number, because the mean of its divisors is an integer number (12371312436).

Almost surely, 2^81297195916 is an apocalyptic number.

It is an amenable number.

81297195916 is a deficient number, since it is larger than the sum of its proper divisors (67158553316).

81297195916 is a wasteful number, since it uses less digits than its factorization.

81297195916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883665200 (or 883665198 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 58.

The spelling of 81297195916 in words is "eighty-one billion, two hundred ninety-seven million, one hundred ninety-five thousand, nine hundred sixteen".