16561617051 has 16 divisors (see below), whose sum is σ = 25238767104. Its totient is φ = 9463024704.

The previous prime is 16561617029. The next prime is 16561617053. The reversal of 16561617051 is 15071616561.

It is not a de Polignac number, because 16561617051 - 2⁵ = 16561617019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16561617053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 338431 + ... + 384263.

It is an arithmetic number, because the mean of its divisors is an integer number (1577422944).

Almost surely, 2^16561617051 is an apocalyptic number.

16561617051 is a deficient number, since it is larger than the sum of its proper divisors (8677150053).

16561617051 is a wasteful number, since it uses less digits than its factorization.

16561617051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63050.

The product of its (nonzero) digits is 37800, while the sum is 39.

The spelling of 16561617051 in words is "sixteen billion, five hundred sixty-one million, six hundred seventeen thousand, fifty-one".