243143531 has 2 divisors, whose sum is σ = 243143532. Its totient is φ = 243143530.

The previous prime is 243143521. The next prime is 243143561. The reversal of 243143531 is 135341342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243143531 - 2¹⁰ = 243142507 is a prime.

It is a super-2 number, since 2×243143531² = 118237553334295922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243143531.

It is not a weakly prime, because it can be changed into another prime (243143501) 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, 121571765 + 121571766.

It is an arithmetic number, because the mean of its divisors is an integer number (121571766).

Almost surely, 2^243143531 is an apocalyptic number.

243143531 is a deficient number, since it is larger than the sum of its proper divisors (1).

243143531 is an equidigital number, since it uses as much as digits as its factorization.

243143531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 26.

The square root of 243143531 is about 15593.0603474751. The cubic root of 243143531 is about 624.1479854952.

Adding to 243143531 its reverse (135341342), we get a palindrome (378484873).

The spelling of 243143531 in words is "two hundred forty-three million, one hundred forty-three thousand, five hundred thirty-one".