261646133266650 has 48 divisors (see below), whose sum is σ = 707871720551328. Its totient is φ = 63429365640000.

The previous prime is 261646133266619. The next prime is 261646133266667. The reversal of 261646133266650 is 56662331646162.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79286705401 + ... + 79286708700.

It is an arithmetic number, because the mean of its divisors is an integer number (14747327511486).

Almost surely, 2^{261646133266650} is an apocalyptic number.

261646133266650 is an abundant number, since it is smaller than the sum of its proper divisors (446225587284678).

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

261646133266650 is a wasteful number, since it uses less digits than its factorization.

261646133266650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158573414127 (or 158573414122 counting only the distinct ones).

The product of its (nonzero) digits is 33592320, while the sum is 57.

The spelling of 261646133266650 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred thirty-three million, two hundred sixty-six thousand, six hundred fifty".