221010100001221 has 2 divisors, whose sum is σ = 221010100001222. Its totient is φ = 221010100001220.

The previous prime is 221010100001147. The next prime is 221010100001261. The reversal of 221010100001221 is 122100001010122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176158884620196 + 44851215381025 = 13272486^2 + 6697105^2 .

It is a cyclic number.

It is not a de Polignac number, because 221010100001221 - 2³³ = 221001510066629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221010100001261) 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, 110505050000610 + 110505050000611.

It is an arithmetic number, because the mean of its divisors is an integer number (110505050000611).

Almost surely, 2^{221010100001221} is an apocalyptic number.

It is an amenable number.

221010100001221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221010100001221 is an equidigital number, since it uses as much as digits as its factorization.

221010100001221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 221010100001221 its reverse (122100001010122), we get a palindrome (343110101011343).

The spelling of 221010100001221 in words is "two hundred twenty-one trillion, ten billion, one hundred million, one thousand, two hundred twenty-one".