243109 has 2 divisors, whose sum is σ = 243110. Its totient is φ = 243108.

The previous prime is 243101. The next prime is 243119. The reversal of 243109 is 901342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178084 + 65025 = 422^2 + 255^2 .

It is a cyclic number.

It is not a de Polignac number, because 243109 - 2³ = 243101 is a prime.

It is equal to p₂₁₄₇₅ and since 243109 and 21475 have the same sum of digits, it is a Honaker prime.

It is a nialpdrome in base 12.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121554 + 121555.

It is an arithmetic number, because the mean of its divisors is an integer number (121555).

2²⁴³¹⁰⁹ is an apocalyptic number.

It is an amenable number.

243109 is a deficient number, since it is larger than the sum of its proper divisors (1).

243109 is an equidigital number, since it uses as much as digits as its factorization.

243109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 243109 is about 493.0608481719. The cubic root of 243109 is about 62.4118437140.

The spelling of 243109 in words is "two hundred forty-three thousand, one hundred nine".