561881880 has 128 divisors (see below), whose sum is σ = 2140531200. Its totient is φ = 128428416.

The previous prime is 561881869. The next prime is 561881893. The reversal of 561881880 is 88188165.

It is a happy number.

561881880 is a `hidden beast` number, since 561 + 8 + 8 + 1 + 8 + 80 = 666.

It is a super-2 number, since 2×561881880² = 631422494144668800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 29602 + ... + 44721.

It is an arithmetic number, because the mean of its divisors is an integer number (16722900).

Almost surely, 2^561881880 is an apocalyptic number.

It is an amenable number.

561881880 is an abundant number, since it is smaller than the sum of its proper divisors (1578649320).

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

561881880 is a wasteful number, since it uses less digits than its factorization.

561881880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74350 (or 74340 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 45.

The square root of 561881880 is about 23704.0477556049. The cubic root of 561881880 is about 825.1793329158.

The spelling of 561881880 in words is "five hundred sixty-one million, eight hundred eighty-one thousand, eight hundred eighty".