221021011011221 has 2 divisors, whose sum is σ = 221021011011222. Its totient is φ = 221021011011220.

The previous prime is 221021011011187. The next prime is 221021011011257. The reversal of 221021011011221 is 122110110120122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189129578448721 + 31891432562500 = 13752439^2 + 5647250^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021011011221 - 2²² = 221021006816917 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221021011011221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221021011017221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510505505610 + 110510505505611.

It is an arithmetic number, because the mean of its divisors is an integer number (110510505505611).

Almost surely, 2^{221021011011221} is an apocalyptic number.

It is an amenable number.

221021011011221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021011011221 is an equidigital number, since it uses as much as digits as its factorization.

221021011011221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 221021011011221 its reverse (122110110120122), we get a palindrome (343131121131343).

The spelling of 221021011011221 in words is "two hundred twenty-one trillion, twenty-one billion, eleven million, eleven thousand, two hundred twenty-one".