256420013 has 2 divisors, whose sum is σ = 256420014. Its totient is φ = 256420012.

The previous prime is 256420007. The next prime is 256420037. The reversal of 256420013 is 310024652.

256420013 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256416169 + 3844 = 16013^2 + 62^2 .

It is a cyclic number.

It is not a de Polignac number, because 256420013 - 2⁴ = 256419997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256420063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128210006 + 128210007.

It is an arithmetic number, because the mean of its divisors is an integer number (128210007).

Almost surely, 2^256420013 is an apocalyptic number.

It is an amenable number.

256420013 is a deficient number, since it is larger than the sum of its proper divisors (1).

256420013 is an equidigital number, since it uses as much as digits as its factorization.

256420013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 256420013 is about 16013.1200270278. The cubic root of 256420013 is about 635.3074857775.

Adding to 256420013 its reverse (310024652), we get a palindrome (566444665).

The spelling of 256420013 in words is "two hundred fifty-six million, four hundred twenty thousand, thirteen".