561765816 has 48 divisors (see below), whose sum is σ = 1610949600. Its totient is φ = 176239872.

The previous prime is 561765793. The next prime is 561765817. The reversal of 561765816 is 618567165.

561765816 is a `hidden beast` number, since 5 + 61 + 7 + 6 + 581 + 6 = 666.

It is a super-2 number, since 2×561765816² = 631161664052291712, which contains 22 as substring.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561765817) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 228256 + ... + 230703.

It is an arithmetic number, because the mean of its divisors is an integer number (33561450).

Almost surely, 2^561765816 is an apocalyptic number.

It is an amenable number.

561765816 is an abundant number, since it is smaller than the sum of its proper divisors (1049183784).

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

561765816 is a wasteful number, since it uses less digits than its factorization.

561765816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458988 (or 458981 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 561765816 is about 23701.5994397003. The cubic root of 561765816 is about 825.1225118337.

The spelling of 561765816 in words is "five hundred sixty-one million, seven hundred sixty-five thousand, eight hundred sixteen".