243639 has 24 divisors (see below), whose sum is σ = 404352. Its totient is φ = 139920.

The previous prime is 243631. The next prime is 243643. The reversal of 243639 is 936342.

243639 is a `hidden beast` number, since 24 + 3 + 639 = 666.

243639 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 243639 - 2³ = 243631 is a prime.

It is a d-powerful number, because it can be written as 2 + 4⁸ + 6³ + 3⁶ + 3¹¹ + 9 .

Its product of digits (3888) is a multiple of the sum of its prime divisors (144).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 243639.

It is not an unprimeable number, because it can be changed into a prime (243631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2224 + ... + 2330.

It is an arithmetic number, because the mean of its divisors is an integer number (16848).

2²⁴³⁶³⁹ is an apocalyptic number.

243639 is a deficient number, since it is larger than the sum of its proper divisors (160713).

243639 is a wasteful number, since it uses less digits than its factorization.

243639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 144 counting only the distinct ones).

The product of its digits is 3888, while the sum is 27.

The square root of 243639 is about 493.5980145827. The cubic root of 243639 is about 62.4571653164.

It can be divided in two parts, 24 and 3639, that added together give a palindrome (3663).

The spelling of 243639 in words is "two hundred forty-three thousand, six hundred thirty-nine".