80521981816 has 32 divisors (see below), whose sum is σ = 154680936480. Its totient is φ = 39273984000.

The previous prime is 80521981811. The next prime is 80521981819. The reversal of 80521981816 is 61818912508.

It is a self number, because there is not a number n which added to its sum of digits gives 80521981816.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80521981811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4715005 + ... + 4732051.

It is an arithmetic number, because the mean of its divisors is an integer number (4833779265).

Almost surely, 2^80521981816 is an apocalyptic number.

It is an amenable number.

80521981816 is a deficient number, since it is larger than the sum of its proper divisors (74158954664).

80521981816 is a wasteful number, since it uses less digits than its factorization.

80521981816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31495 (or 31491 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 49.

The spelling of 80521981816 in words is "eighty billion, five hundred twenty-one million, nine hundred eighty-one thousand, eight hundred sixteen".