220101221 has 2 divisors, whose sum is σ = 220101222. Its totient is φ = 220101220.

The previous prime is 220101181. The next prime is 220101229. The reversal of 220101221 is 122101022.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110145025 + 109956196 = 10495^2 + 10486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220101221 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220101229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110050610 + 110050611.

It is an arithmetic number, because the mean of its divisors is an integer number (110050611).

Almost surely, 2^220101221 is an apocalyptic number.

It is an amenable number.

220101221 is a deficient number, since it is larger than the sum of its proper divisors (1).

220101221 is an equidigital number, since it uses as much as digits as its factorization.

220101221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 220101221 is about 14835.8087410158. The cubic root of 220101221 is about 603.7736431236.

Adding to 220101221 its reverse (122101022), we get a palindrome (342202243).

The spelling of 220101221 in words is "two hundred twenty million, one hundred one thousand, two hundred twenty-one".