2561730165 has 64 divisors (see below), whose sum is σ = 4653158400. Its totient is φ = 1336896000.

The previous prime is 2561730161. The next prime is 2561730169. The reversal of 2561730165 is 5610371652.

2561730165 is a `hidden beast` number, since 2 + 5 + 617 + 30 + 1 + 6 + 5 = 666.

2561730165 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2561730161) and next prime (2561730169).

It is not a de Polignac number, because 2561730165 - 2² = 2561730161 is a prime.

It is a super-2 number, since 2×2561730165² = 13124922876541854450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561730161) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1212460 + ... + 1214570.

It is an arithmetic number, because the mean of its divisors is an integer number (72705600).

Almost surely, 2^2561730165 is an apocalyptic number.

It is an amenable number.

2561730165 is a deficient number, since it is larger than the sum of its proper divisors (2091428235).

2561730165 is a wasteful number, since it uses less digits than its factorization.

2561730165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2315 (or 2309 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 2561730165 is about 50613.5373689688. The cubic root of 2561730165 is about 1368.2888692453.

The spelling of 2561730165 in words is "two billion, five hundred sixty-one million, seven hundred thirty thousand, one hundred sixty-five".