243851 has 2 divisors, whose sum is σ = 243852. Its totient is φ = 243850.

The previous prime is 243839. The next prime is 243857. The reversal of 243851 is 158342.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 243851 - 2⁶ = 243787 is a prime.

It is a Sophie Germain prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 243851.

It is not a weakly prime, because it can be changed into another prime (243857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121925 + 121926.

It is an arithmetic number, because the mean of its divisors is an integer number (121926).

2²⁴³⁸⁵¹ is an apocalyptic number.

243851 is a deficient number, since it is larger than the sum of its proper divisors (1).

243851 is an equidigital number, since it uses as much as digits as its factorization.

243851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 23.

The square root of 243851 is about 493.8127175357. The cubic root of 243851 is about 62.4752755539.

The spelling of 243851 in words is "two hundred forty-three thousand, eight hundred fifty-one".