16561377 has 24 divisors (see below), whose sum is σ = 27497600. Its totient is φ = 9408960.

The previous prime is 16561367. The next prime is 16561379. The reversal of 16561377 is 77316561.

It is not a de Polignac number, because 16561377 - 2⁴ = 16561361 is a prime.

It is a super-2 number, since 2×16561377² = 548558416272258, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16561379) 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, 11877 + ... + 13197.

Almost surely, 2^16561377 is an apocalyptic number.

It is an amenable number.

16561377 is a deficient number, since it is larger than the sum of its proper divisors (10936223).

16561377 is a wasteful number, since it uses less digits than its factorization.

16561377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1533 (or 1530 counting only the distinct ones).

The product of its digits is 26460, while the sum is 36.

The square root of 16561377 is about 4069.5671760029. The cubic root of 16561377 is about 254.8974443423.

The spelling of 16561377 in words is "sixteen million, five hundred sixty-one thousand, three hundred seventy-seven".