261766447426741 has 2 divisors, whose sum is σ = 261766447426742. Its totient is φ = 261766447426740.

The previous prime is 261766447426739. The next prime is 261766447426811. The reversal of 261766447426741 is 147624744667162.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141483769143025 + 120282678283716 = 11894695^2 + 10967346^2 .

It is a cyclic number.

It is not a de Polignac number, because 261766447426741 - 2¹ = 261766447426739 is a prime.

Together with 261766447426739, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261766447426711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130883223713370 + 130883223713371.

It is an arithmetic number, because the mean of its divisors is an integer number (130883223713371).

Almost surely, 2^{261766447426741} is an apocalyptic number.

It is an amenable number.

261766447426741 is a deficient number, since it is larger than the sum of its proper divisors (1).

261766447426741 is an equidigital number, since it uses as much as digits as its factorization.

261766447426741 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 455196672, while the sum is 67.

The spelling of 261766447426741 in words is "two hundred sixty-one trillion, seven hundred sixty-six billion, four hundred forty-seven million, four hundred twenty-six thousand, seven hundred forty-one".