561998880 has 144 divisors (see below), whose sum is σ = 1924715520. Its totient is φ = 149328384.

The previous prime is 561998873. The next prime is 561998887. The reversal of 561998880 is 88899165.

It is an interprime number because it is at equal distance from previous prime (561998873) and next prime (561998887).

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×561998880² = 631685482242508800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (561998887) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 551011 + ... + 552029.

It is an arithmetic number, because the mean of its divisors is an integer number (13366080).

Almost surely, 2^561998880 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 561998880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (962357760).

561998880 is an abundant number, since it is smaller than the sum of its proper divisors (1362716640).

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

561998880 is a wasteful number, since it uses less digits than its factorization.

561998880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1423 (or 1412 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 54.

The square root of 561998880 is about 23706.5155600734. The cubic root of 561998880 is about 825.2366043133.

The spelling of 561998880 in words is "five hundred sixty-one million, nine hundred ninety-eight thousand, eight hundred eighty".