261646665631464 has 32 divisors (see below), whose sum is σ = 654122798212320. Its totient is φ = 87214737326016.

The previous prime is 261646665631447. The next prime is 261646665631513. The reversal of 261646665631464 is 464136566646162.

It is a junction number, because it is equal to n+sod(n) for n = 261646665631395 and 261646665631404.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48502479 + ... + 53626334.

It is an arithmetic number, because the mean of its divisors is an integer number (20441337444135).

Almost surely, 2^{261646665631464} is an apocalyptic number.

261646665631464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261646665631464 is an abundant number, since it is smaller than the sum of its proper divisors (392476132580856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261646665631464 is a wasteful number, since it uses less digits than its factorization.

261646665631464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102235569 (or 102235565 counting only the distinct ones).

The product of its digits is 537477120, while the sum is 66.

The spelling of 261646665631464 in words is "two hundred sixty-one trillion, six hundred forty-six billion, six hundred sixty-five million, six hundred thirty-one thousand, four hundred sixty-four".