561999375 has 90 divisors (see below), whose sum is σ = 1180590840. Its totient is φ = 256788000.

The previous prime is 561999371. The next prime is 561999397. The reversal of 561999375 is 573999165.

561999375 is a `hidden beast` number, since 561 + 9 + 9 + 9 + 3 + 75 = 666.

It is not a de Polignac number, because 561999375 - 2² = 561999371 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561999371) by changing a digit.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 274606 + ... + 276644.

It is an arithmetic number, because the mean of its divisors is an integer number (13117676).

Almost surely, 2^561999375 is an apocalyptic number.

561999375 is an abundant number, since it is smaller than the sum of its proper divisors (618591465).

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

561999375 is a wasteful number, since it uses less digits than its factorization.

561999375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2079 (or 2054 counting only the distinct ones).

The product of its digits is 2296350, while the sum is 54.

The square root of 561999375 is about 23706.5260002388. The cubic root of 561999375 is about 825.2368465985.

The spelling of 561999375 in words is "five hundred sixty-one million, nine hundred ninety-nine thousand, three hundred seventy-five".