257813819 has 2 divisors, whose sum is σ = 257813820. Its totient is φ = 257813818.

The previous prime is 257813813. The next prime is 257813821. The reversal of 257813819 is 918318752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257813819 - 2¹² = 257809723 is a prime.

It is a super-2 number, since 2×257813819² = 132935930534729522, which contains 22 as substring.

Together with 257813821, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 257813819.

It is not a weakly prime, because it can be changed into another prime (257813813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128906909 + 128906910.

It is an arithmetic number, because the mean of its divisors is an integer number (128906910).

Almost surely, 2^257813819 is an apocalyptic number.

257813819 is a deficient number, since it is larger than the sum of its proper divisors (1).

257813819 is an equidigital number, since it uses as much as digits as its factorization.

257813819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 44.

The square root of 257813819 is about 16056.5817968832. The cubic root of 257813819 is about 636.4565065999.

The spelling of 257813819 in words is "two hundred fifty-seven million, eight hundred thirteen thousand, eight hundred nineteen".