561866624 has 64 divisors (see below), whose sum is σ = 1251013680. Its totient is φ = 249139200.

The previous prime is 561866597. The next prime is 561866653. The reversal of 561866624 is 426668165.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52862 + ... + 62594.

Almost surely, 2^561866624 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 561866624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (625506840).

561866624 is an abundant number, since it is smaller than the sum of its proper divisors (689147056).

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

561866624 is a wasteful number, since it uses less digits than its factorization.

561866624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9799 (or 9787 counting only the distinct ones).

The product of its digits is 414720, while the sum is 44.

The square root of 561866624 is about 23703.7259518414. The cubic root of 561866624 is about 825.1718645313.

The spelling of 561866624 in words is "five hundred sixty-one million, eight hundred sixty-six thousand, six hundred twenty-four".