561665172 has 12 divisors (see below), whose sum is σ = 1310552096. Its totient is φ = 187221720.

The previous prime is 561665171. The next prime is 561665177. The reversal of 561665172 is 271566165.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 561665172.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561665171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23402704 + ... + 23402727.

Almost surely, 2^561665172 is an apocalyptic number.

It is an amenable number.

561665172 is an abundant number, since it is smaller than the sum of its proper divisors (748886924).

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

561665172 is a wasteful number, since it uses less digits than its factorization.

561665172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46805438 (or 46805436 counting only the distinct ones).

The product of its digits is 75600, while the sum is 39.

The square root of 561665172 is about 23699.4761967433. The cubic root of 561665172 is about 825.0732335357.

The spelling of 561665172 in words is "five hundred sixty-one million, six hundred sixty-five thousand, one hundred seventy-two".