268688405257 has 2 divisors, whose sum is σ = 268688405258. Its totient is φ = 268688405256.

The previous prime is 268688405233. The next prime is 268688405261. The reversal of 268688405257 is 752504886862.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 262278161161 + 6410244096 = 512131^2 + 80064^2 .

It is a cyclic number.

It is not a de Polignac number, because 268688405257 - 2¹¹ = 268688403209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 268688405195 and 268688405204.

It is not a weakly prime, because it can be changed into another prime (268688405957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134344202628 + 134344202629.

It is an arithmetic number, because the mean of its divisors is an integer number (134344202629).

Almost surely, 2^268688405257 is an apocalyptic number.

It is an amenable number.

268688405257 is a deficient number, since it is larger than the sum of its proper divisors (1).

268688405257 is an equidigital number, since it uses as much as digits as its factorization.

268688405257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51609600, while the sum is 61.

The spelling of 268688405257 in words is "two hundred sixty-eight billion, six hundred eighty-eight million, four hundred five thousand, two hundred fifty-seven".