261646175564413 has 16 divisors (see below), whose sum is σ = 279532541481840. Its totient is φ = 244037760311296.

The previous prime is 261646175564357. The next prime is 261646175564479. The reversal of 261646175564413 is 314465571646162.

It can be written as a sum of positive squares in 8 ways, for example, as 91212680584089 + 170433494980324 = 9550533^2 + 13055018^2 .

It is a cyclic number.

It is not a de Polignac number, because 261646175564413 - 2³⁷ = 261508736610941 is a prime.

It is a super-2 number, since 2×261646175564413² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261646175564483) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1614081 + ... + 22932457.

It is an arithmetic number, because the mean of its divisors is an integer number (17470783842615).

Almost surely, 2^{261646175564413} is an apocalyptic number.

It is an amenable number.

261646175564413 is a deficient number, since it is larger than the sum of its proper divisors (17886365917427).

261646175564413 is a wasteful number, since it uses less digits than its factorization.

261646175564413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21324896.

The product of its digits is 87091200, while the sum is 61.

The spelling of 261646175564413 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred seventy-five million, five hundred sixty-four thousand, four hundred thirteen".