261922329457 has 2 divisors, whose sum is σ = 261922329458. Its totient is φ = 261922329456.

The previous prime is 261922329443. The next prime is 261922329463. The reversal of 261922329457 is 754923229162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208155850081 + 53766479376 = 456241^2 + 231876^2 .

It is a cyclic number.

It is not a de Polignac number, because 261922329457 - 2⁷ = 261922329329 is a prime.

It is not a weakly prime, because it can be changed into another prime (261922329437) 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, 130961164728 + 130961164729.

It is an arithmetic number, because the mean of its divisors is an integer number (130961164729).

Almost surely, 2^261922329457 is an apocalyptic number.

It is an amenable number.

261922329457 is a deficient number, since it is larger than the sum of its proper divisors (1).

261922329457 is an equidigital number, since it uses as much as digits as its factorization.

261922329457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 52.

The spelling of 261922329457 in words is "two hundred sixty-one billion, nine hundred twenty-two million, three hundred twenty-nine thousand, four hundred fifty-seven".