221121112001221 has 2 divisors, whose sum is σ = 221121112001222. Its totient is φ = 221121112001220.

The previous prime is 221121112001191. The next prime is 221121112001281. The reversal of 221121112001221 is 122100211121122.

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., 128899373664996 + 92221738336225 = 11353386^2 + 9603215^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121112001221 - 2⁴³ = 212325018979013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221121112001281) 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, 110560556000610 + 110560556000611.

It is an arithmetic number, because the mean of its divisors is an integer number (110560556000611).

Almost surely, 2^{221121112001221} is an apocalyptic number.

It is an amenable number.

221121112001221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121112001221 is an equidigital number, since it uses as much as digits as its factorization.

221121112001221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 221121112001221 its reverse (122100211121122), we get a palindrome (343221323122343).

The spelling of 221121112001221 in words is "two hundred twenty-one trillion, one hundred twenty-one billion, one hundred twelve million, one thousand, two hundred twenty-one".