242409 has 4 divisors (see below), whose sum is σ = 323216. Its totient is φ = 161604.

The previous prime is 242399. The next prime is 242413. The reversal of 242409 is 904242.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 242409 - 2⁴ = 242393 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (242419) 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 in 3 ways as a sum of consecutive naturals, for example, 40399 + ... + 40404.

It is an arithmetic number, because the mean of its divisors is an integer number (80804).

2²⁴²⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

242409 is a deficient number, since it is larger than the sum of its proper divisors (80807).

242409 is an equidigital number, since it uses as much as digits as its factorization.

242409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80806.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 242409 is about 492.3504849190. The cubic root of 242409 is about 62.3518839300.

The spelling of 242409 in words is "two hundred forty-two thousand, four hundred nine".