243643 has 2 divisors, whose sum is σ = 243644. Its totient is φ = 243642.

The previous prime is 243631. The next prime is 243647. The reversal of 243643 is 346342.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 243643 - 2¹⁷ = 112571 is a prime.

It is a super-2 number, since 2×243643² = 118723822898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (243647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121821 + 121822.

It is an arithmetic number, because the mean of its divisors is an integer number (121822).

2²⁴³⁶⁴³ is an apocalyptic number.

243643 is a deficient number, since it is larger than the sum of its proper divisors (1).

243643 is an equidigital number, since it uses as much as digits as its factorization.

243643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 22.

The square root of 243643 is about 493.6020664462. The cubic root of 243643 is about 62.4575071162.

Adding to 243643 its reverse (346342), we get a palindrome (589985).

The spelling of 243643 in words is "two hundred forty-three thousand, six hundred forty-three".