561565500 has 96 divisors (see below), whose sum is σ = 1641826368. Its totient is φ = 149152000.

The previous prime is 561565453. The next prime is 561565519. The reversal of 561565500 is 5565165.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 474910 + ... + 476090.

It is an arithmetic number, because the mean of its divisors is an integer number (17102358).

Almost surely, 2^561565500 is an apocalyptic number.

561565500 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561565500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (820913184).

561565500 is an abundant number, since it is smaller than the sum of its proper divisors (1080260868).

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

561565500 is a wasteful number, since it uses less digits than its factorization.

561565500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1520 (or 1508 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 33.

The square root of 561565500 is about 23697.3732721582. The cubic root of 561565500 is about 825.0244253558.

The spelling of 561565500 in words is "five hundred sixty-one million, five hundred sixty-five thousand, five hundred".