16581644812 has 24 divisors (see below), whose sum is σ = 31001042240. Its totient is φ = 7737230160.

The previous prime is 16581644743. The next prime is 16581644837. The reversal of 16581644812 is 21844618561.

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, 1623114 + ... + 1633297.

Almost surely, 2^16581644812 is an apocalyptic number.

It is an amenable number.

16581644812 is a deficient number, since it is larger than the sum of its proper divisors (14419397428).

16581644812 is a wasteful number, since it uses less digits than its factorization.

16581644812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3256501 (or 3256499 counting only the distinct ones).

The product of its digits is 368640, while the sum is 46.

The spelling of 16581644812 in words is "sixteen billion, five hundred eighty-one million, six hundred forty-four thousand, eight hundred twelve".