121242221 has 2 divisors, whose sum is σ = 121242222. Its totient is φ = 121242220.

The previous prime is 121242193. The next prime is 121242293. The reversal of 121242221 is 122242121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121242121 + 100 = 11011^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 121242221 - 2¹⁴ = 121225837 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 121242221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121245221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60621110 + 60621111.

It is an arithmetic number, because the mean of its divisors is an integer number (60621111).

Almost surely, 2^121242221 is an apocalyptic number.

It is an amenable number.

121242221 is a deficient number, since it is larger than the sum of its proper divisors (1).

121242221 is an equidigital number, since it uses as much as digits as its factorization.

121242221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 17.

The square root of 121242221 is about 11011.0045409127. The cubic root of 121242221 is about 494.9385646300.

Adding to 121242221 its reverse (122242121), we get a palindrome (243484342).

The spelling of 121242221 in words is "one hundred twenty-one million, two hundred forty-two thousand, two hundred twenty-one".