243644 has 12 divisors (see below), whose sum is σ = 451584. Its totient is φ = 114624.

The previous prime is 243643. The next prime is 243647. The reversal of 243644 is 446342.

243644 = 171² + 172² + ... + 178².

It is a happy number.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1724 + ... + 1859.

It is an arithmetic number, because the mean of its divisors is an integer number (37632).

2²⁴³⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

243644 is a deficient number, since it is larger than the sum of its proper divisors (207940).

243644 is a wasteful number, since it uses less digits than its factorization.

243644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3604 (or 3602 counting only the distinct ones).

The product of its digits is 2304, while the sum is 23.

The square root of 243644 is about 493.6030794069. The cubic root of 243644 is about 62.4575925656.

Adding to 243644 its reverse (446342), we get a palindrome (689986).

The spelling of 243644 in words is "two hundred forty-three thousand, six hundred forty-four".