561611556 has 60 divisors (see below), whose sum is σ = 1601643120. Its totient is φ = 170184240.

The previous prime is 561611551. The next prime is 561611579. The reversal of 561611556 is 655116165.

It is a super-2 number, since 2×561611556² = 630815079665482272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 561611556.

It is not an unprimeable number, because it can be changed into a prime (561611551) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 75226 + ... + 82353.

It is an arithmetic number, because the mean of its divisors is an integer number (26694052).

Almost surely, 2^561611556 is an apocalyptic number.

It is an amenable number.

561611556 is an abundant number, since it is smaller than the sum of its proper divisors (1040031564).

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

561611556 is a wasteful number, since it uses less digits than its factorization.

561611556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157606 (or 157595 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The square root of 561611556 is about 23698.3450055062. The cubic root of 561611556 is about 825.0469791429.

The spelling of 561611556 in words is "five hundred sixty-one million, six hundred eleven thousand, five hundred fifty-six".