209221 has 2 divisors, whose sum is σ = 209222. Its totient is φ = 209220.

The previous prime is 209213. The next prime is 209227. The reversal of 209221 is 122902.

It is a happy number.

209221 is nontrivially palindromic in base 14.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152100 + 57121 = 390^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 209221 - 2³ = 209213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 209195 and 209204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104610 + 104611.

It is an arithmetic number, because the mean of its divisors is an integer number (104611).

2²⁰⁹²²¹ is an apocalyptic number.

It is an amenable number.

209221 is a deficient number, since it is larger than the sum of its proper divisors (1).

209221 is an equidigital number, since it uses as much as digits as its factorization.

209221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 209221 is about 457.4068211122. The cubic root of 209221 is about 59.3656313935.

The spelling of 209221 in words is "two hundred nine thousand, two hundred twenty-one".