243865 has 16 divisors (see below), whose sum is σ = 328320. Its totient is φ = 172800.

The previous prime is 243863. The next prime is 243871. The reversal of 243865 is 568342.

It is not a de Polignac number, because 243865 - 2¹ = 243863 is a prime.

Its product of digits (5760) is a multiple of the sum of its prime divisors (192).

It is not an unprimeable number, because it can be changed into a prime (243863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1540 + ... + 1690.

It is an arithmetic number, because the mean of its divisors is an integer number (20520).

2²⁴³⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

243865 is a deficient number, since it is larger than the sum of its proper divisors (84455).

243865 is a wasteful number, since it uses less digits than its factorization.

243865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192.

The product of its digits is 5760, while the sum is 28.

The square root of 243865 is about 493.8268927468. The cubic root of 243865 is about 62.4764711434.

The spelling of 243865 in words is "two hundred forty-three thousand, eight hundred sixty-five".