257340616261 has 2 divisors, whose sum is σ = 257340616262. Its totient is φ = 257340616260.

The previous prime is 257340616243. The next prime is 257340616301. The reversal of 257340616261 is 162616043752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137897109025 + 119443507236 = 371345^2 + 345606^2 .

It is a cyclic number.

It is not a de Polignac number, because 257340616261 - 2⁵ = 257340616229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257340611261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128670308130 + 128670308131.

It is an arithmetic number, because the mean of its divisors is an integer number (128670308131).

Almost surely, 2^257340616261 is an apocalyptic number.

It is an amenable number.

257340616261 is a deficient number, since it is larger than the sum of its proper divisors (1).

257340616261 is an equidigital number, since it uses as much as digits as its factorization.

257340616261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 43.

The spelling of 257340616261 in words is "two hundred fifty-seven billion, three hundred forty million, six hundred sixteen thousand, two hundred sixty-one".