561812720 has 160 divisors (see below), whose sum is σ = 1589041152. Its totient is φ = 180550656.

The previous prime is 561812717. The next prime is 561812723. The reversal of 561812720 is 27218165.

561812720 = T₃₈₈ + T₃₈₉ + ... + T₁₅₀₇.

It is an interprime number because it is at equal distance from previous prime (561812717) and next prime (561812723).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561812723) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 682229 + ... + 683051.

Almost surely, 2^561812720 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 561812720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (794520576).

561812720 is an abundant number, since it is smaller than the sum of its proper divisors (1027228432).

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

561812720 is a wasteful number, since it uses less digits than its factorization.

561812720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919 (or 913 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 561812720 is about 23702.5888881362. The cubic root of 561812720 is about 825.1454754176.

The spelling of 561812720 in words is "five hundred sixty-one million, eight hundred twelve thousand, seven hundred twenty".