261646133264415 has 24 divisors (see below), whose sum is σ = 462076944788160. Its totient is φ = 136911687342144.

The previous prime is 261646133264389. The next prime is 261646133264419. The reversal of 261646133264415 is 514462331646162.

261646133264415 is a `hidden beast` number, since 2 + 6 + 1 + 6 + 4 + 613 + 3 + 2 + 6 + 4 + 4 + 15 = 666.

It is not a de Polignac number, because 261646133264415 - 2¹² = 261646133260319 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261646133264419) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54852436455 + ... + 54852441224.

It is an arithmetic number, because the mean of its divisors is an integer number (19253206032840).

Almost surely, 2^{261646133264415} is an apocalyptic number.

261646133264415 is a deficient number, since it is larger than the sum of its proper divisors (200430811523745).

261646133264415 is a wasteful number, since it uses less digits than its factorization.

261646133264415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109704877743 (or 109704877740 counting only the distinct ones).

The product of its digits is 14929920, while the sum is 54.

The spelling of 261646133264415 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred thirty-three million, two hundred sixty-four thousand, four hundred fifteen".