242809 has 4 divisors (see below), whose sum is σ = 277504. Its totient is φ = 208116.

The previous prime is 242807. The next prime is 242813. The reversal of 242809 is 908242.

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 a cyclic number.

It is not a de Polignac number, because 242809 - 2¹ = 242807 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (242807) 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, 17337 + ... + 17350.

It is an arithmetic number, because the mean of its divisors is an integer number (69376).

2²⁴²⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

242809 is a deficient number, since it is larger than the sum of its proper divisors (34695).

242809 is an equidigital number, since it uses as much as digits as its factorization.

242809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34694.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 242809 is about 492.7565321739. The cubic root of 242809 is about 62.3861607760.

The spelling of 242809 in words is "two hundred forty-two thousand, eight hundred nine".