256051813 has 2 divisors, whose sum is σ = 256051814. Its totient is φ = 256051812.

The previous prime is 256051811. The next prime is 256051819. The reversal of 256051813 is 318150652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 181090849 + 74960964 = 13457^2 + 8658^2 .

It is a cyclic number.

It is not a de Polignac number, because 256051813 - 2¹ = 256051811 is a prime.

Together with 256051811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256051811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128025906 + 128025907.

It is an arithmetic number, because the mean of its divisors is an integer number (128025907).

Almost surely, 2^256051813 is an apocalyptic number.

It is an amenable number.

256051813 is a deficient number, since it is larger than the sum of its proper divisors (1).

256051813 is an equidigital number, since it uses as much as digits as its factorization.

256051813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 256051813 is about 16001.6190743312. The cubic root of 256051813 is about 635.0032554032.

The spelling of 256051813 in words is "two hundred fifty-six million, fifty-one thousand, eight hundred thirteen".