261421770164273 has 2 divisors, whose sum is σ = 261421770164274. Its totient is φ = 261421770164272.

The previous prime is 261421770164231. The next prime is 261421770164299. The reversal of 261421770164273 is 372461077124162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162029783144464 + 99391987019809 = 12729092^2 + 9969553^2 .

It is a cyclic number.

It is not a de Polignac number, because 261421770164273 - 2⁸ = 261421770164017 is a prime.

It is not a weakly prime, because it can be changed into another prime (261421770164213) 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, 130710885082136 + 130710885082137.

It is an arithmetic number, because the mean of its divisors is an integer number (130710885082137).

Almost surely, 2^{261421770164273} is an apocalyptic number.

It is an amenable number.

261421770164273 is a deficient number, since it is larger than the sum of its proper divisors (1).

261421770164273 is an equidigital number, since it uses as much as digits as its factorization.

261421770164273 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4741632, while the sum is 53.

The spelling of 261421770164273 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, seven hundred seventy million, one hundred sixty-four thousand, two hundred seventy-three".