257340618641 has 2 divisors, whose sum is σ = 257340618642. Its totient is φ = 257340618640.

The previous prime is 257340618629. The next prime is 257340618643. The reversal of 257340618641 is 146816043752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 256968900241 + 371718400 = 506921^2 + 19280^2 .

It is a cyclic number.

It is not a de Polignac number, because 257340618641 - 2¹⁰ = 257340617617 is a prime.

Together with 257340618643, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (257340618643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128670309320 + 128670309321.

It is an arithmetic number, because the mean of its divisors is an integer number (128670309321).

Almost surely, 2^257340618641 is an apocalyptic number.

It is an amenable number.

257340618641 is a deficient number, since it is larger than the sum of its proper divisors (1).

257340618641 is an equidigital number, since it uses as much as digits as its factorization.

257340618641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 967680, while the sum is 47.

The spelling of 257340618641 in words is "two hundred fifty-seven billion, three hundred forty million, six hundred eighteen thousand, six hundred forty-one".