81987846616 has 32 divisors (see below), whose sum is σ = 169590254400. Its totient is φ = 36917602560.

The previous prime is 81987846587. The next prime is 81987846631. The reversal of 81987846616 is 61664878918.

It is a congruent number.

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, 9609696 + ... + 9618223.

It is an arithmetic number, because the mean of its divisors is an integer number (5299695450).

Almost surely, 2^81987846616 is an apocalyptic number.

It is an amenable number.

81987846616 is an abundant number, since it is smaller than the sum of its proper divisors (87602407784).

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

81987846616 is a wasteful number, since it uses less digits than its factorization.

81987846616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19227979 (or 19227975 counting only the distinct ones).

The product of its digits is 27869184, while the sum is 64.

The spelling of 81987846616 in words is "eighty-one billion, nine hundred eighty-seven million, eight hundred forty-six thousand, six hundred sixteen".