261431275332511 has 4 divisors (see below), whose sum is σ = 261438229994224. Its totient is φ = 261424320670800.

The previous prime is 261431275332467. The next prime is 261431275332683. The reversal of 261431275332511 is 115233572134162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261431275332511 is a prime.

It is a super-2 number, since 2×261431275332511² (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 (261431275332011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3477274470 + ... + 3477349651.

It is an arithmetic number, because the mean of its divisors is an integer number (65359557498556).

Almost surely, 2^{261431275332511} is an apocalyptic number.

261431275332511 is a deficient number, since it is larger than the sum of its proper divisors (6954661713).

261431275332511 is an equidigital number, since it uses as much as digits as its factorization.

261431275332511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6954661712.

The product of its digits is 907200, while the sum is 46.

The spelling of 261431275332511 in words is "two hundred sixty-one trillion, four hundred thirty-one billion, two hundred seventy-five million, three hundred thirty-two thousand, five hundred eleven".