16561016616 has 64 divisors (see below), whose sum is σ = 43852536000. Its totient is φ = 5193888768.

The previous prime is 16561016587. The next prime is 16561016617. The reversal of 16561016616 is 61661016561.

It is not an unprimeable number, because it can be changed into a prime (16561016617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1851531 + ... + 1860453.

It is an arithmetic number, because the mean of its divisors is an integer number (685195875).

Almost surely, 2^16561016616 is an apocalyptic number.

It is an amenable number.

16561016616 is an abundant number, since it is smaller than the sum of its proper divisors (27291519384).

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

16561016616 is a wasteful number, since it uses less digits than its factorization.

16561016616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13498 (or 13494 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 16561016616 in words is "sixteen billion, five hundred sixty-one million, sixteen thousand, six hundred sixteen".