561994368 has 128 divisors (see below), whose sum is σ = 1624721280. Its totient is φ = 171085824.

The previous prime is 561994361. The next prime is 561994373. The reversal of 561994368 is 863499165.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 561994368.

It is not an unprimeable number, because it can be changed into a prime (561994361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 513630 + ... + 514722.

It is an arithmetic number, because the mean of its divisors is an integer number (12693135).

Almost surely, 2^561994368 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 561994368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (812360640).

561994368 is an abundant number, since it is smaller than the sum of its proper divisors (1062726912).

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

561994368 is a wasteful number, since it uses less digits than its factorization.

561994368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1226 (or 1214 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 51.

The square root of 561994368 is about 23706.4203961712. The cubic root of 561994368 is about 825.2343958407.

The spelling of 561994368 in words is "five hundred sixty-one million, nine hundred ninety-four thousand, three hundred sixty-eight".