243504643 has 2 divisors, whose sum is σ = 243504644. Its totient is φ = 243504642.

The previous prime is 243504607. The next prime is 243504649. The reversal of 243504643 is 346405342.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243504643 is a prime.

It is a super-2 number, since 2×243504643² = 118589022325114898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (243504649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121752321 + 121752322.

It is an arithmetic number, because the mean of its divisors is an integer number (121752322).

Almost surely, 2^243504643 is an apocalyptic number.

243504643 is a deficient number, since it is larger than the sum of its proper divisors (1).

243504643 is an equidigital number, since it uses as much as digits as its factorization.

243504643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 31.

The square root of 243504643 is about 15604.6353049342. The cubic root of 243504643 is about 624.4568234315.

Adding to 243504643 its reverse (346405342), we get a palindrome (589909985).

The spelling of 243504643 in words is "two hundred forty-three million, five hundred four thousand, six hundred forty-three".