243979 has 4 divisors (see below), whose sum is σ = 256840. Its totient is φ = 231120.

The previous prime is 243973. The next prime is 243989. The reversal of 243979 is 979342.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 243979 - 2⁷ = 243851 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6402 + ... + 6439.

It is an arithmetic number, because the mean of its divisors is an integer number (64210).

2²⁴³⁹⁷⁹ is an apocalyptic number.

243979 is a deficient number, since it is larger than the sum of its proper divisors (12861).

243979 is a wasteful number, since it uses less digits than its factorization.

243979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12860.

The product of its digits is 13608, while the sum is 34.

The square root of 243979 is about 493.9423043231. The cubic root of 243979 is about 62.4862049554.

The spelling of 243979 in words is "two hundred forty-three thousand, nine hundred seventy-nine".