256430021213 has 2 divisors, whose sum is σ = 256430021214. Its totient is φ = 256430021212.

The previous prime is 256430021173. The next prime is 256430021219. The reversal of 256430021213 is 312120034652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165875369284 + 90554651929 = 407278^2 + 300923^2 .

It is a cyclic number.

It is not a de Polignac number, because 256430021213 - 2⁶ = 256430021149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256430021219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128215010606 + 128215010607.

It is an arithmetic number, because the mean of its divisors is an integer number (128215010607).

Almost surely, 2^256430021213 is an apocalyptic number.

It is an amenable number.

256430021213 is a deficient number, since it is larger than the sum of its proper divisors (1).

256430021213 is an equidigital number, since it uses as much as digits as its factorization.

256430021213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 29.

Adding to 256430021213 its reverse (312120034652), we get a palindrome (568550055865).

The spelling of 256430021213 in words is "two hundred fifty-six billion, four hundred thirty million, twenty-one thousand, two hundred thirteen".