1256819 has 2 divisors, whose sum is σ = 1256820. Its totient is φ = 1256818.

The previous prime is 1256813. The next prime is 1256821. The reversal of 1256819 is 9186521.

It is a strong prime.

It is an emirp because it is prime and its reverse (9186521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1256819 - 2¹⁶ = 1191283 is a prime.

It is a super-2 number, since 2×1256819² = 3159187997522, which contains 22 as substring.

Together with 1256821, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1256813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628409 + 628410.

It is an arithmetic number, because the mean of its divisors is an integer number (628410).

2^1256819 is an apocalyptic number.

1256819 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256819 is an equidigital number, since it uses as much as digits as its factorization.

1256819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 32.

The square root of 1256819 is about 1121.0793905875. The cubic root of 1256819 is about 107.9172605888.

The spelling of 1256819 in words is "one million, two hundred fifty-six thousand, eight hundred nineteen".