257478782819 has 2 divisors, whose sum is σ = 257478782820. Its totient is φ = 257478782818.

The previous prime is 257478782807. The next prime is 257478782849. The reversal of 257478782819 is 918287874752.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257478782819 is a prime.

It is a super-2 number, since 2×257478782819² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257478782849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128739391409 + 128739391410.

It is an arithmetic number, because the mean of its divisors is an integer number (128739391410).

Almost surely, 2^257478782819 is an apocalyptic number.

257478782819 is a deficient number, since it is larger than the sum of its proper divisors (1).

257478782819 is an equidigital number, since it uses as much as digits as its factorization.

257478782819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 126443520, while the sum is 68.

The spelling of 257478782819 in words is "two hundred fifty-seven billion, four hundred seventy-eight million, seven hundred eighty-two thousand, eight hundred nineteen".