561805916 has 12 divisors (see below), whose sum is σ = 1123611888. Its totient is φ = 240773952.

The previous prime is 561805873. The next prime is 561805931. The reversal of 561805916 is 619508165.

561805916 is an admirable number.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10032221 + ... + 10032276.

It is an arithmetic number, because the mean of its divisors is an integer number (93634324).

Almost surely, 2^561805916 is an apocalyptic number.

It is an amenable number.

561805916 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

561805916 is a wasteful number, since it uses less digits than its factorization.

561805916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20064508 (or 20064506 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 41.

The square root of 561805916 is about 23702.4453590763. The cubic root of 561805916 is about 825.1421443476.

The spelling of 561805916 in words is "five hundred sixty-one million, eight hundred five thousand, nine hundred sixteen".