243994 has 4 divisors (see below), whose sum is σ = 365994. Its totient is φ = 121996.

The previous prime is 243989. The next prime is 244003. The reversal of 243994 is 499342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 499342 = 2 ⋅249671.

It can be written as a sum of positive squares in only one way, i.e., 131769 + 112225 = 363^2 + 335^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60997 + ... + 61000.

2²⁴³⁹⁹⁴ is an apocalyptic number.

243994 is a deficient number, since it is larger than the sum of its proper divisors (122000).

243994 is a wasteful number, since it uses less digits than its factorization.

243994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121999.

The product of its digits is 7776, while the sum is 31.

The square root of 243994 is about 493.9574880493. The cubic root of 243994 is about 62.4874854944.

The spelling of 243994 in words is "two hundred forty-three thousand, nine hundred ninety-four".