243861 has 8 divisors (see below), whose sum is σ = 336480. Its totient is φ = 156912.

The previous prime is 243857. The next prime is 243863. The reversal of 243861 is 168342.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 243861 - 2² = 243857 is a prime.

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 243861.

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 7 ways as a sum of consecutive naturals, for example, 1315 + ... + 1488.

It is an arithmetic number, because the mean of its divisors is an integer number (42060).

2²⁴³⁸⁶¹ is an apocalyptic number.

It is an amenable number.

243861 is a deficient number, since it is larger than the sum of its proper divisors (92619).

243861 is a wasteful number, since it uses less digits than its factorization.

243861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2835.

The product of its digits is 1152, while the sum is 24.

The square root of 243861 is about 493.8228427280. The cubic root of 243861 is about 62.4761295511.

The spelling of 243861 in words is "two hundred forty-three thousand, eight hundred sixty-one".