121221100212221 has 2 divisors, whose sum is σ = 121221100212222. Its totient is φ = 121221100212220.

The previous prime is 121221100212181. The next prime is 121221100212241. The reversal of 121221100212221 is 122212001122121.

It is an a-pointer prime, because the next prime (121221100212241) can be obtained adding 121221100212221 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89545151608900 + 31675948603321 = 9462830^2 + 5628139^2 .

It is a cyclic number.

It is not a de Polignac number, because 121221100212221 - 2³⁸ = 120946222305277 is a prime.

It is a super-2 number, since 2×121221100212221² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121221100212193 and 121221100212202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121221100212241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610550106110 + 60610550106111.

It is an arithmetic number, because the mean of its divisors is an integer number (60610550106111).

Almost surely, 2^{121221100212221} is an apocalyptic number.

It is an amenable number.

121221100212221 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221100212221 is an equidigital number, since it uses as much as digits as its factorization.

121221100212221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 121221100212221 its reverse (122212001122121), we get a palindrome (243433101334342).

The spelling of 121221100212221 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, one hundred million, two hundred twelve thousand, two hundred twenty-one".