261646133266667 has 2 divisors, whose sum is σ = 261646133266668. Its totient is φ = 261646133266666.

The previous prime is 261646133266619. The next prime is 261646133266691. The reversal of 261646133266667 is 766662331646162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261646133266667 - 2⁸ = 261646133266411 is a prime.

It is not a weakly prime, because it can be changed into another prime (261646133266367) by changing a digit.

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 as a sum of consecutive naturals, namely, 130823066633333 + 130823066633334.

It is an arithmetic number, because the mean of its divisors is an integer number (130823066633334).

Almost surely, 2^{261646133266667} is an apocalyptic number.

261646133266667 is a deficient number, since it is larger than the sum of its proper divisors (1).

261646133266667 is an equidigital number, since it uses as much as digits as its factorization.

261646133266667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282175488, while the sum is 65.

The spelling of 261646133266667 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 sixty-seven".