256163522221 has 2 divisors, whose sum is σ = 256163522222. Its totient is φ = 256163522220.

The previous prime is 256163522203. The next prime is 256163522273. The reversal of 256163522221 is 122225361652.

256163522221 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., 250050002500 + 6113519721 = 500050^2 + 78189^2 .

It is a cyclic number.

It is not a de Polignac number, because 256163522221 - 2⁷ = 256163522093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256163525221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128081761110 + 128081761111.

It is an arithmetic number, because the mean of its divisors is an integer number (128081761111).

Almost surely, 2^256163522221 is an apocalyptic number.

It is an amenable number.

256163522221 is a deficient number, since it is larger than the sum of its proper divisors (1).

256163522221 is an equidigital number, since it uses as much as digits as its factorization.

256163522221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 86400, while the sum is 37.

Adding to 256163522221 its reverse (122225361652), we get a palindrome (378388883873).

The spelling of 256163522221 in words is "two hundred fifty-six billion, one hundred sixty-three million, five hundred twenty-two thousand, two hundred twenty-one".