561557268 has 36 divisors (see below), whose sum is σ = 1425453120. Its totient is φ = 186399696.

The previous prime is 561557263. The next prime is 561557317. The reversal of 561557268 is 862755165.

561557268 is a `hidden beast` number, since 5 + 6 + 15 + 572 + 68 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561557263) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24030 + ... + 41237.

It is an arithmetic number, because the mean of its divisors is an integer number (39595920).

Almost surely, 2^561557268 is an apocalyptic number.

It is an amenable number.

561557268 is an abundant number, since it is smaller than the sum of its proper divisors (863895852).

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

561557268 is a wasteful number, since it uses less digits than its factorization.

561557268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65516 (or 65511 counting only the distinct ones).

The product of its digits is 504000, while the sum is 45.

The square root of 561557268 is about 23697.1995813851. The cubic root of 561557268 is about 825.0203939862.

The spelling of 561557268 in words is "five hundred sixty-one million, five hundred fifty-seven thousand, two hundred sixty-eight".