221206169 has 2 divisors, whose sum is σ = 221206170. Its totient is φ = 221206168.

The previous prime is 221206127. The next prime is 221206213. The reversal of 221206169 is 961602122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168091225 + 53114944 = 12965^2 + 7288^2 .

It is a cyclic number.

It is not a de Polignac number, because 221206169 - 2⁸ = 221205913 is a prime.

It is a super-2 number, since 2×221206169² = 97864338407313122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221200169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110603084 + 110603085.

It is an arithmetic number, because the mean of its divisors is an integer number (110603085).

Almost surely, 2^221206169 is an apocalyptic number.

It is an amenable number.

221206169 is a deficient number, since it is larger than the sum of its proper divisors (1).

221206169 is an equidigital number, since it uses as much as digits as its factorization.

221206169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 221206169 is about 14873.0013447186. The cubic root of 221206169 is about 604.7823081282.

The spelling of 221206169 in words is "two hundred twenty-one million, two hundred six thousand, one hundred sixty-nine".