243931 has 2 divisors, whose sum is σ = 243932. Its totient is φ = 243930.

The previous prime is 243917. The next prime is 243953. The reversal of 243931 is 139342.

It is an a-pointer prime, because the next prime (243953) can be obtained adding 243931 to its sum of digits (22).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243931 - 2¹¹ = 241883 is a prime.

It is a super-2 number, since 2×243931² = 119004665522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (243911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121965 + 121966.

It is an arithmetic number, because the mean of its divisors is an integer number (121966).

2²⁴³⁹³¹ is an apocalyptic number.

243931 is a deficient number, since it is larger than the sum of its proper divisors (1).

243931 is an equidigital number, since it uses as much as digits as its factorization.

243931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 22.

The square root of 243931 is about 493.8937132623. The cubic root of 243931 is about 62.4821068779.

The spelling of 243931 in words is "two hundred forty-three thousand, nine hundred thirty-one".