561665236 has 24 divisors (see below), whose sum is σ = 1072973664. Its totient is φ = 255134880.

The previous prime is 561665231. The next prime is 561665281. The reversal of 561665236 is 632566165.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561665231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84946 + ... + 91318.

It is an arithmetic number, because the mean of its divisors is an integer number (44707236).

Almost surely, 2^561665236 is an apocalyptic number.

It is an amenable number.

561665236 is a deficient number, since it is larger than the sum of its proper divisors (511308428).

561665236 is a wasteful number, since it uses less digits than its factorization.

561665236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8391 (or 8389 counting only the distinct ones).

The product of its digits is 194400, while the sum is 40.

The square root of 561665236 is about 23699.4775469840. The cubic root of 561665236 is about 825.0732648739.

The spelling of 561665236 in words is "five hundred sixty-one million, six hundred sixty-five thousand, two hundred thirty-six".