261315752517 has 12 divisors (see below), whose sum is σ = 377580412300. Its totient is φ = 174153120768.

The previous prime is 261315752513. The next prime is 261315752519. The reversal of 261315752517 is 715257513162.

261315752517 is a `hidden beast` number, since 2 + 6 + 1 + 31 + 57 + 52 + 517 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 214715463876 + 46600288641 = 463374^2 + 215871^2 .

It is not a de Polignac number, because 261315752517 - 2² = 261315752513 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261315752513) 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, 4752892 + ... + 4807557.

Almost surely, 2^261315752517 is an apocalyptic number.

It is an amenable number.

261315752517 is a deficient number, since it is larger than the sum of its proper divisors (116264659783).

261315752517 is a wasteful number, since it uses less digits than its factorization.

261315752517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9563492 (or 9563489 counting only the distinct ones).

The product of its digits is 441000, while the sum is 45.

The spelling of 261315752517 in words is "two hundred sixty-one billion, three hundred fifteen million, seven hundred fifty-two thousand, five hundred seventeen".