243819 has 6 divisors (see below), whose sum is σ = 352196. Its totient is φ = 162540.

The previous prime is 243809. The next prime is 243829. The reversal of 243819 is 918342.

It is an interprime number because it is at equal distance from previous prime (243809) and next prime (243829).

It is not a de Polignac number, because 243819 - 2⁵ = 243787 is a prime.

It is a super-2 number, since 2×243819² = 118895409522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 243792 and 243801.

It is not an unprimeable number, because it can be changed into a prime (243809) 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 5 ways as a sum of consecutive naturals, for example, 13537 + ... + 13554.

2²⁴³⁸¹⁹ is an apocalyptic number.

243819 is a deficient number, since it is larger than the sum of its proper divisors (108377).

243819 is a wasteful number, since it uses less digits than its factorization.

243819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27097 (or 27094 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 243819 is about 493.7803155250. The cubic root of 243819 is about 62.4725426059.

The spelling of 243819 in words is "two hundred forty-three thousand, eight hundred nineteen".