261665431006044 has 96 divisors (see below), whose sum is σ = 692899142874624. Its totient is φ = 76249405267200.

The previous prime is 261665431006037. The next prime is 261665431006079. The reversal of 261665431006044 is 440600134566162.

It is a junction number, because it is equal to n+sod(n) for n = 261665431005984 and 261665431006002.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 360666994 + ... + 361391769.

It is an arithmetic number, because the mean of its divisors is an integer number (7217699404944).

Almost surely, 2^{261665431006044} is an apocalyptic number.

It is an amenable number.

261665431006044 is an abundant number, since it is smaller than the sum of its proper divisors (431233711868580).

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

261665431006044 is a wasteful number, since it uses less digits than its factorization.

261665431006044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722058907 (or 722058905 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 48.

The spelling of 261665431006044 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, four hundred thirty-one million, six thousand, forty-four".