243400643 has 4 divisors (see below), whose sum is σ = 243502560. Its totient is φ = 243298728.

The previous prime is 243400631. The next prime is 243400657. The reversal of 243400643 is 346004342.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 243400643 - 2⁶ = 243400579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243400673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47288 + ... + 52181.

It is an arithmetic number, because the mean of its divisors is an integer number (60875640).

Almost surely, 2^243400643 is an apocalyptic number.

243400643 is a deficient number, since it is larger than the sum of its proper divisors (101917).

243400643 is an equidigital number, since it uses as much as digits as its factorization.

243400643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101916.

The product of its (nonzero) digits is 6912, while the sum is 26.

The square root of 243400643 is about 15601.3026058724. The cubic root of 243400643 is about 624.3679096477.

Adding to 243400643 its reverse (346004342), we get a palindrome (589404985).

The spelling of 243400643 in words is "two hundred forty-three million, four hundred thousand, six hundred forty-three".