561665331 has 12 divisors (see below), whose sum is σ = 815142120. Its totient is φ = 372667680.

The previous prime is 561665311. The next prime is 561665333. The reversal of 561665331 is 133566165.

561665331 is a `hidden beast` number, since 5 + 61 + 66 + 533 + 1 = 666.

561665331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 561665331 - 2¹⁴ = 561648947 is a prime.

It is a super-2 number, since 2×561665331² = 630935888094679122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (561665333) 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, 145986 + ... + 149783.

It is an arithmetic number, because the mean of its divisors is an integer number (67928510).

Almost surely, 2^561665331 is an apocalyptic number.

561665331 is a deficient number, since it is larger than the sum of its proper divisors (253476789).

561665331 is a wasteful number, since it uses less digits than its factorization.

561665331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295986 (or 295983 counting only the distinct ones).

The product of its digits is 48600, while the sum is 36.

The square root of 561665331 is about 23699.4795512475. The cubic root of 561665331 is about 825.0733113915.

The spelling of 561665331 in words is "five hundred sixty-one million, six hundred sixty-five thousand, three hundred thirty-one".