561011640 has 128 divisors (see below), whose sum is σ = 1928655360. Its totient is φ = 127885824.

The previous prime is 561011603. The next prime is 561011663. The reversal of 561011640 is 46110165.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 561011640.

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, 438682 + ... + 439958.

It is an arithmetic number, because the mean of its divisors is an integer number (15067620).

Almost surely, 2^561011640 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 561011640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (964327680).

561011640 is an abundant number, since it is smaller than the sum of its proper divisors (1367643720).

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

561011640 is a wasteful number, since it uses less digits than its factorization.

561011640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1821 (or 1817 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 561011640 is about 23685.6842839720. The cubic root of 561011640 is about 824.7531015081.

The spelling of 561011640 in words is "five hundred sixty-one million, eleven thousand, six hundred forty".