16561570374 has 48 divisors (see below), whose sum is σ = 38245914720. Its totient is φ = 5161363200.

The previous prime is 16561570373. The next prime is 16561570379. The reversal of 16561570374 is 47307516561.

16561570374 is a `hidden beast` number, since 1 + 6 + 5 + 6 + 1 + 570 + 3 + 74 = 666.

It is a super-2 number, since 2×16561570374² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561570373) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 133009 + ... + 225420.

It is an arithmetic number, because the mean of its divisors is an integer number (796789890).

Almost surely, 2^16561570374 is an apocalyptic number.

16561570374 is an abundant number, since it is smaller than the sum of its proper divisors (21684344346).

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

16561570374 is a wasteful number, since it uses less digits than its factorization.

16561570374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358605 (or 358602 counting only the distinct ones).

The product of its (nonzero) digits is 529200, while the sum is 45.

The spelling of 16561570374 in words is "sixteen billion, five hundred sixty-one million, five hundred seventy thousand, three hundred seventy-four".