221421169 has 2 divisors, whose sum is σ = 221421170. Its totient is φ = 221421168.

The previous prime is 221421157. The next prime is 221421173. The reversal of 221421169 is 961124122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214329600 + 7091569 = 14640^2 + 2663^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221421169 is a prime.

It is a super-2 number, since 2×221421169² = 98054668162653122, which contains 22 as substring.

It is a Chen prime.

It is equal to p_12196504 and since 221421169 and 12196504 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (221421869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110710584 + 110710585.

It is an arithmetic number, because the mean of its divisors is an integer number (110710585).

Almost surely, 2^221421169 is an apocalyptic number.

It is an amenable number.

221421169 is a deficient number, since it is larger than the sum of its proper divisors (1).

221421169 is an equidigital number, since it uses as much as digits as its factorization.

221421169 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 28.

The square root of 221421169 is about 14880.2274512186. The cubic root of 221421169 is about 604.9781828528.

The spelling of 221421169 in words is "two hundred twenty-one million, four hundred twenty-one thousand, one hundred sixty-nine".