561878640 has 160 divisors (see below), whose sum is σ = 2037369600. Its totient is φ = 141937920.

The previous prime is 561878563. The next prime is 561878651. The reversal of 561878640 is 46878165.

It is a happy number.

561878640 is a `hidden beast` number, since 561 + 8 + 7 + 86 + 4 + 0 = 666.

561878640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 34195 + ... + 47885.

It is an arithmetic number, because the mean of its divisors is an integer number (12733560).

Almost surely, 2^561878640 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 561878640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1018684800).

561878640 is an abundant number, since it is smaller than the sum of its proper divisors (1475490960).

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

561878640 is a wasteful number, since it uses less digits than its factorization.

561878640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13732 (or 13720 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 561878640 is about 23703.9794127484. The cubic root of 561878640 is about 825.1777468255.

The spelling of 561878640 in words is "five hundred sixty-one million, eight hundred seventy-eight thousand, six hundred forty".