261431265021770 has 64 divisors (see below), whose sum is σ = 473183526816000. Its totient is φ = 103994743910400.

The previous prime is 261431265021769. The next prime is 261431265021781. The reversal of 261431265021770 is 77120562134162.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18995216909 + ... + 18995230671.

It is an arithmetic number, because the mean of its divisors is an integer number (7393492606500).

Almost surely, 2^{261431265021770} is an apocalyptic number.

261431265021770 is a deficient number, since it is larger than the sum of its proper divisors (211752261794230).

261431265021770 is a wasteful number, since it uses less digits than its factorization.

261431265021770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27791.

The product of its (nonzero) digits is 846720, while the sum is 47.

The spelling of 261431265021770 in words is "two hundred sixty-one trillion, four hundred thirty-one billion, two hundred sixty-five million, twenty-one thousand, seven hundred seventy".