16561056616 has 64 divisors (see below), whose sum is σ = 33660506880. Its totient is φ = 7593488640.

The previous prime is 16561056607. The next prime is 16561056641. The reversal of 16561056616 is 61665016561.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13452721 + ... + 13453951.

It is an arithmetic number, because the mean of its divisors is an integer number (525945420).

Almost surely, 2^16561056616 is an apocalyptic number.

It is an amenable number.

16561056616 is an abundant number, since it is smaller than the sum of its proper divisors (17099450264).

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

16561056616 is a wasteful number, since it uses less digits than its factorization.

16561056616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1994 (or 1990 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 16561056616 in words is "sixteen billion, five hundred sixty-one million, fifty-six thousand, six hundred sixteen".