261665121723056 has 20 divisors (see below), whose sum is σ = 509549656457952. Its totient is φ = 130168436185536.

The previous prime is 261665121723023. The next prime is 261665121723073. The reversal of 261665121723056 is 650327121566162.

It is a junction number, because it is equal to n+sod(n) for n = 261665121722989 and 261665121723007.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41507789000 + ... + 41507795303.

Almost surely, 2^{261665121723056} is an apocalyptic number.

It is an amenable number.

261665121723056 is a deficient number, since it is larger than the sum of its proper divisors (247884534734896).

261665121723056 is a wasteful number, since it uses less digits than its factorization.

261665121723056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83015584508 (or 83015584502 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 53.

The spelling of 261665121723056 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, one hundred twenty-one million, seven hundred twenty-three thousand, fifty-six".