561855720 has 64 divisors (see below), whose sum is σ = 1691752320. Its totient is φ = 149278464.

The previous prime is 561855667. The next prime is 561855739. The reversal of 561855720 is 27558165.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24789 + ... + 41691.

It is an arithmetic number, because the mean of its divisors is an integer number (26433630).

Almost surely, 2^561855720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561855720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (845876160).

561855720 is an abundant number, since it is smaller than the sum of its proper divisors (1129896600).

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

561855720 is a wasteful number, since it uses less digits than its factorization.

561855720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17194 (or 17190 counting only the distinct ones).

The product of its (nonzero) digits is 84000, while the sum is 39.

The square root of 561855720 is about 23703.4959446914. The cubic root of 561855720 is about 825.1665265312.

The spelling of 561855720 in words is "five hundred sixty-one million, eight hundred fifty-five thousand, seven hundred twenty".