257896666481 has 2 divisors, whose sum is σ = 257896666482. Its totient is φ = 257896666480.

The previous prime is 257896666373. The next prime is 257896666487. The reversal of 257896666481 is 184666698752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221614036081 + 36282630400 = 470759^2 + 190480^2 .

It is a cyclic number.

It is not a de Polignac number, because 257896666481 - 2¹⁴ = 257896650097 is a prime.

It is a super-2 number, since 2×257896666481² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257896666487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128948333240 + 128948333241.

It is an arithmetic number, because the mean of its divisors is an integer number (128948333241).

Almost surely, 2^257896666481 is an apocalyptic number.

It is an amenable number.

257896666481 is a deficient number, since it is larger than the sum of its proper divisors (1).

257896666481 is an equidigital number, since it uses as much as digits as its factorization.

257896666481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209018880, while the sum is 68.

The spelling of 257896666481 in words is "two hundred fifty-seven billion, eight hundred ninety-six million, six hundred sixty-six thousand, four hundred eighty-one".