256222222621 has 2 divisors, whose sum is σ = 256222222622. Its totient is φ = 256222222620.

The previous prime is 256222222609. The next prime is 256222222657. The reversal of 256222222621 is 126222222652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213985807396 + 42236415225 = 462586^2 + 205515^2 .

It is a cyclic number.

It is not a de Polignac number, because 256222222621 - 2²⁵ = 256188668189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256222222601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128111111310 + 128111111311.

It is an arithmetic number, because the mean of its divisors is an integer number (128111111311).

Almost surely, 2^256222222621 is an apocalyptic number.

It is an amenable number.

256222222621 is a deficient number, since it is larger than the sum of its proper divisors (1).

256222222621 is an equidigital number, since it uses as much as digits as its factorization.

256222222621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46080, while the sum is 34.

The spelling of 256222222621 in words is "two hundred fifty-six billion, two hundred twenty-two million, two hundred twenty-two thousand, six hundred twenty-one".