256813369 has 2 divisors, whose sum is σ = 256813370. Its totient is φ = 256813368.

The previous prime is 256813363. The next prime is 256813379. The reversal of 256813369 is 963318652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 246490000 + 10323369 = 15700^2 + 3213^2 .

It is a cyclic number.

It is not a de Polignac number, because 256813369 - 2¹³ = 256805177 is a prime.

It is a super-2 number, since 2×256813369² = 131906212994260322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (256813363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128406684 + 128406685.

It is an arithmetic number, because the mean of its divisors is an integer number (128406685).

Almost surely, 2^256813369 is an apocalyptic number.

It is an amenable number.

256813369 is a deficient number, since it is larger than the sum of its proper divisors (1).

256813369 is an equidigital number, since it uses as much as digits as its factorization.

256813369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 43.

The square root of 256813369 is about 16025.3976237721. The cubic root of 256813369 is about 635.6321800575.

The spelling of 256813369 in words is "two hundred fifty-six million, eight hundred thirteen thousand, three hundred sixty-nine".