221331209221 has 2 divisors, whose sum is σ = 221331209222. Its totient is φ = 221331209220.

The previous prime is 221331209207. The next prime is 221331209243. The reversal of 221331209221 is 122902133122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153738489025 + 67592720196 = 392095^2 + 259986^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221331209221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221331209221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221331209251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110665604610 + 110665604611.

It is an arithmetic number, because the mean of its divisors is an integer number (110665604611).

Almost surely, 2^221331209221 is an apocalyptic number.

It is an amenable number.

221331209221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221331209221 is an equidigital number, since it uses as much as digits as its factorization.

221331209221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 221331209221 in words is "two hundred twenty-one billion, three hundred thirty-one million, two hundred nine thousand, two hundred twenty-one".