220121121221 has 2 divisors, whose sum is σ = 220121121222. Its totient is φ = 220121121220.

The previous prime is 220121121203. The next prime is 220121121247. The reversal of 220121121221 is 122121121022.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 143148722500 + 76972398721 = 378350^2 + 277439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220121121221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 220121121221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220121123221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110060560610 + 110060560611.

It is an arithmetic number, because the mean of its divisors is an integer number (110060560611).

Almost surely, 2^220121121221 is an apocalyptic number.

It is an amenable number.

220121121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

220121121221 is an equidigital number, since it uses as much as digits as its factorization.

220121121221 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 17.

Adding to 220121121221 its reverse (122121121022), we get a palindrome (342242242243).

The spelling of 220121121221 in words is "two hundred twenty billion, one hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".