243143591 has 2 divisors, whose sum is σ = 243143592. Its totient is φ = 243143590.

The previous prime is 243143587. The next prime is 243143599. The reversal of 243143591 is 195341342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243143591 - 2² = 243143587 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243143599) 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 as a sum of consecutive naturals, namely, 121571795 + 121571796.

It is an arithmetic number, because the mean of its divisors is an integer number (121571796).

Almost surely, 2^243143591 is an apocalyptic number.

243143591 is a deficient number, since it is larger than the sum of its proper divisors (1).

243143591 is an equidigital number, since it uses as much as digits as its factorization.

243143591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 32.

The square root of 243143591 is about 15593.0622714078. The cubic root of 243143591 is about 624.1480368351.

The spelling of 243143591 in words is "two hundred forty-three million, one hundred forty-three thousand, five hundred ninety-one".