221020313221 has 2 divisors, whose sum is σ = 221020313222. Its totient is φ = 221020313220.

The previous prime is 221020313209. The next prime is 221020313231. The reversal of 221020313221 is 122313020122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 215283008196 + 5737305025 = 463986^2 + 75745^2 .

It is a cyclic number.

It is not a de Polignac number, because 221020313221 - 2⁷ = 221020313093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221020313201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510156610 + 110510156611.

It is an arithmetic number, because the mean of its divisors is an integer number (110510156611).

Almost surely, 2^221020313221 is an apocalyptic number.

It is an amenable number.

221020313221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221020313221 is an equidigital number, since it uses as much as digits as its factorization.

221020313221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 221020313221 its reverse (122313020122), we get a palindrome (343333333343).

The spelling of 221020313221 in words is "two hundred twenty-one billion, twenty million, three hundred thirteen thousand, two hundred twenty-one".