261440712145871 has 2 divisors, whose sum is σ = 261440712145872. Its totient is φ = 261440712145870.

The previous prime is 261440712145741. The next prime is 261440712145891. The reversal of 261440712145871 is 178541217044162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261440712145871 - 2⁴² = 257042665634767 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261440712145891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130720356072935 + 130720356072936.

It is an arithmetic number, because the mean of its divisors is an integer number (130720356072936).

Almost surely, 2^{261440712145871} is an apocalyptic number.

261440712145871 is a deficient number, since it is larger than the sum of its proper divisors (1).

261440712145871 is an equidigital number, since it uses as much as digits as its factorization.

261440712145871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3010560, while the sum is 53.

The spelling of 261440712145871 in words is "two hundred sixty-one trillion, four hundred forty billion, seven hundred twelve million, one hundred forty-five thousand, eight hundred seventy-one".