257720743305287 has 2 divisors, whose sum is σ = 257720743305288. Its totient is φ = 257720743305286.

The previous prime is 257720743305241. The next prime is 257720743305317. The reversal of 257720743305287 is 782503347027752.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257720743305287 - 2⁸ = 257720743305031 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257720743305187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128860371652643 + 128860371652644.

It is an arithmetic number, because the mean of its divisors is an integer number (128860371652644).

Almost surely, 2^{257720743305287} is an apocalyptic number.

257720743305287 is a deficient number, since it is larger than the sum of its proper divisors (1).

257720743305287 is an equidigital number, since it uses as much as digits as its factorization.

257720743305287 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138297600, while the sum is 62.

The spelling of 257720743305287 in words is "two hundred fifty-seven trillion, seven hundred twenty billion, seven hundred forty-three million, three hundred five thousand, two hundred eighty-seven".