42209 has 2 divisors, whose sum is σ = 42210. Its totient is φ = 42208.

The previous prime is 42197. The next prime is 42221. The reversal of 42209 is 90224.

42209 is nontrivially palindromic in base 11.

It is a balanced prime because it is at equal distance from previous prime (42197) and next prime (42221).

It can be written as a sum of positive squares in only one way, i.e., 40000 + 2209 = 200^2 + 47^2 .

It is a cyclic number.

It is not a de Polignac number, because 42209 - 2⁴ = 42193 is a prime.

It is a magnanimous number.

It is not a weakly prime, because it can be changed into another prime (42239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21104 + 21105.

It is an arithmetic number, because the mean of its divisors is an integer number (21105).

2⁴²²⁰⁹ is an apocalyptic number.

It is an amenable number.

42209 is a deficient number, since it is larger than the sum of its proper divisors (1).

42209 is an equidigital number, since it uses as much as digits as its factorization.

42209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 42209 is about 205.4482903312. The cubic root of 42209 is about 34.8178289758.

It can be divided in two parts, 42 and 209, that multiplied together give a palindrome (8778).

The spelling of 42209 in words is "forty-two thousand, two hundred nine".