16556122165561 has 8 divisors (see below), whose sum is σ = 19011814927200. Its totient is φ = 14258861195040.

The previous prime is 16556122165549. The next prime is 16556122165571.

16556122165561 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16556122165561 - 2⁹ = 16556122165049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16556122165499 and 16556122165508.

It is not an unprimeable number, because it can be changed into a prime (16556122165571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39607947556 + ... + 39607947973.

It is an arithmetic number, because the mean of its divisors is an integer number (2376476865900).

Almost surely, 2^{16556122165561} is an apocalyptic number.

16556122165561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16556122165561 is a deficient number, since it is larger than the sum of its proper divisors (2455692761639).

16556122165561 is a wasteful number, since it uses less digits than its factorization.

16556122165561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79215895559.

The product of its digits is 3240000, while the sum is 52.

The spelling of 16556122165561 in words is "sixteen trillion, five hundred fifty-six billion, one hundred twenty-two million, one hundred sixty-five thousand, five hundred sixty-one".