256434221 has 2 divisors, whose sum is σ = 256434222. Its totient is φ = 256434220.

The previous prime is 256434197. The next prime is 256434229. The reversal of 256434221 is 122434652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 199204996 + 57229225 = 14114^2 + 7565^2 .

It is a cyclic number.

It is not a de Polignac number, because 256434221 - 2¹⁰ = 256433197 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256434229) 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, 128217110 + 128217111.

It is an arithmetic number, because the mean of its divisors is an integer number (128217111).

Almost surely, 2^256434221 is an apocalyptic number.

It is an amenable number.

256434221 is a deficient number, since it is larger than the sum of its proper divisors (1).

256434221 is an equidigital number, since it uses as much as digits as its factorization.

256434221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 29.

The square root of 256434221 is about 16013.5636571002. The cubic root of 256434221 is about 635.3192194977.

Adding to 256434221 its reverse (122434652), we get a palindrome (378868873).

The spelling of 256434221 in words is "two hundred fifty-six million, four hundred thirty-four thousand, two hundred twenty-one".