257409886861 has 2 divisors, whose sum is σ = 257409886862. Its totient is φ = 257409886860.

The previous prime is 257409886849. The next prime is 257409886931. The reversal of 257409886861 is 168688904752.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213804512100 + 43605374761 = 462390^2 + 208819^2 .

It is a cyclic number.

It is not a de Polignac number, because 257409886861 - 2⁵ = 257409886829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 257409886793 and 257409886802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257409886961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128704943430 + 128704943431.

It is an arithmetic number, because the mean of its divisors is an integer number (128704943431).

Almost surely, 2^257409886861 is an apocalyptic number.

It is an amenable number.

257409886861 is a deficient number, since it is larger than the sum of its proper divisors (1).

257409886861 is an equidigital number, since it uses as much as digits as its factorization.

257409886861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46448640, while the sum is 64.

The spelling of 257409886861 in words is "two hundred fifty-seven billion, four hundred nine million, eight hundred eighty-six thousand, eight hundred sixty-one".