561316840 has 128 divisors (see below), whose sum is σ = 1541928960. Its totient is φ = 179714304.

The previous prime is 561316781. The next prime is 561316849. The reversal of 561316840 is 48613165.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 561316796 and 561316805.

It is not an unprimeable number, because it can be changed into a prime (561316849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 275907 + ... + 277933.

It is an arithmetic number, because the mean of its divisors is an integer number (12046320).

Almost surely, 2^561316840 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 561316840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (770964480).

561316840 is an abundant number, since it is smaller than the sum of its proper divisors (980612120).

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

561316840 is a wasteful number, since it uses less digits than its factorization.

561316840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2111 (or 2107 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 561316840 is about 23692.1261181853. The cubic root of 561316840 is about 824.9026343619.

The spelling of 561316840 in words is "five hundred sixty-one million, three hundred sixteen thousand, eight hundred forty".