257127079817 has 2 divisors, whose sum is σ = 257127079818. Its totient is φ = 257127079816.

The previous prime is 257127079777. The next prime is 257127079829. The reversal of 257127079817 is 718970721752.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206348513536 + 50778566281 = 454256^2 + 225341^2 .

It is a cyclic number.

It is not a de Polignac number, because 257127079817 - 2¹⁶ = 257127014281 is a prime.

It is a super-2 number, since 2×257127079817² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257127079897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128563539908 + 128563539909.

It is an arithmetic number, because the mean of its divisors is an integer number (128563539909).

Almost surely, 2^257127079817 is an apocalyptic number.

It is an amenable number.

257127079817 is a deficient number, since it is larger than the sum of its proper divisors (1).

257127079817 is an equidigital number, since it uses as much as digits as its factorization.

257127079817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3457440, while the sum is 56.

The spelling of 257127079817 in words is "two hundred fifty-seven billion, one hundred twenty-seven million, seventy-nine thousand, eight hundred seventeen".