243949 has 4 divisors (see below), whose sum is σ = 246780. Its totient is φ = 241120.

The previous prime is 243931. The next prime is 243953. The reversal of 243949 is 949342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 949342 = 2 ⋅474671.

It can be written as a sum of positive squares in 2 ways, for example, as 59049 + 184900 = 243^2 + 430^2 .

It is a cyclic number.

It is not a de Polignac number, because 243949 - 2⁵ = 243917 is a prime.

It is a super-2 number, since 2×243949² = 119022229202, which contains 22 as substring.

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 a d-powerful number, because it can be written as 2⁹ + 4² + 9 + 3¹¹ + 4⁸ + 9³ .

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 243949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243989) 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, 1282 + ... + 1459.

It is an arithmetic number, because the mean of its divisors is an integer number (61695).

2²⁴³⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

243949 is a deficient number, since it is larger than the sum of its proper divisors (2831).

243949 is an equidigital number, since it uses as much as digits as its factorization.

243949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2830.

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

The square root of 243949 is about 493.9119354703. The cubic root of 243949 is about 62.4836437199.

The spelling of 243949 in words is "two hundred forty-three thousand, nine hundred forty-nine".