16561656155 has 32 divisors (see below), whose sum is σ = 21809813760. Its totient is φ = 11973339520.

The previous prime is 16561656151. The next prime is 16561656229. The reversal of 16561656155 is 55165616561.

It is not a de Polignac number, because 16561656155 - 2² = 16561656151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16561656151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8683712 + ... + 8685618.

It is an arithmetic number, because the mean of its divisors is an integer number (681556680).

Almost surely, 2^16561656155 is an apocalyptic number.

16561656155 is a deficient number, since it is larger than the sum of its proper divisors (5248157605).

16561656155 is a wasteful number, since it uses less digits than its factorization.

16561656155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2779.

The product of its digits is 810000, while the sum is 47.

The spelling of 16561656155 in words is "sixteen billion, five hundred sixty-one million, six hundred fifty-six thousand, one hundred fifty-five".