256352221 has 2 divisors, whose sum is σ = 256352222. Its totient is φ = 256352220.

The previous prime is 256352203. The next prime is 256352267. The reversal of 256352221 is 122253652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256352121 + 100 = 16011^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 256352221 - 2⁷ = 256352093 is a prime.

It is a super-2 number, since 2×256352221² = 131432922423265682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 256352221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256352281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128176110 + 128176111.

It is an arithmetic number, because the mean of its divisors is an integer number (128176111).

Almost surely, 2^256352221 is an apocalyptic number.

It is an amenable number.

256352221 is a deficient number, since it is larger than the sum of its proper divisors (1).

256352221 is an equidigital number, since it uses as much as digits as its factorization.

256352221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7200, while the sum is 28.

The square root of 256352221 is about 16011.0031228527. The cubic root of 256352221 is about 635.2514935786.

The spelling of 256352221 in words is "two hundred fifty-six million, three hundred fifty-two thousand, two hundred twenty-one".