261432521577 has 6 divisors (see below), whose sum is σ = 377624753402. Its totient is φ = 174288347712.

The previous prime is 261432521551. The next prime is 261432521617. The reversal of 261432521577 is 775125234162.

261432521577 is a `hidden beast` number, since 2 + 61 + 432 + 5 + 2 + 157 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 260626586256 + 805935321 = 510516^2 + 28389^2 .

It is not a de Polignac number, because 261432521577 - 2¹⁰ = 261432520553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261432521177) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14524028968 + ... + 14524028985.

Almost surely, 2^261432521577 is an apocalyptic number.

It is an amenable number.

261432521577 is a deficient number, since it is larger than the sum of its proper divisors (116192231825).

261432521577 is a wasteful number, since it uses less digits than its factorization.

261432521577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29048057959 (or 29048057956 counting only the distinct ones).

The product of its digits is 705600, while the sum is 45.

The spelling of 261432521577 in words is "two hundred sixty-one billion, four hundred thirty-two million, five hundred twenty-one thousand, five hundred seventy-seven".