561256287 has 4 divisors (see below), whose sum is σ = 748341720. Its totient is φ = 374170856.

The previous prime is 561256277. The next prime is 561256291. The reversal of 561256287 is 782652165.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 561256287 - 2²² = 557061983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561256247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93542712 + ... + 93542717.

It is an arithmetic number, because the mean of its divisors is an integer number (187085430).

Almost surely, 2^561256287 is an apocalyptic number.

561256287 is a deficient number, since it is larger than the sum of its proper divisors (187085433).

561256287 is a wasteful number, since it uses less digits than its factorization.

561256287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187085432.

The product of its digits is 201600, while the sum is 42.

The square root of 561256287 is about 23690.8481697047. The cubic root of 561256287 is about 824.8729707080.

The spelling of 561256287 in words is "five hundred sixty-one million, two hundred fifty-six thousand, two hundred eighty-seven".