1243042543 has 2 divisors, whose sum is σ = 1243042544. Its totient is φ = 1243042542.

The previous prime is 1243042523. The next prime is 1243042547. The reversal of 1243042543 is 3452403421.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243042543 is a prime.

It is a super-4 number, since 4×1243042543⁴ (a number of 37 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243042547) 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, 621521271 + 621521272.

It is an arithmetic number, because the mean of its divisors is an integer number (621521272).

Almost surely, 2^1243042543 is an apocalyptic number.

1243042543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243042543 is an equidigital number, since it uses as much as digits as its factorization.

1243042543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 28.

The square root of 1243042543 is about 35256.8084630472. The cubic root of 1243042543 is about 1075.2150405937.

Adding to 1243042543 its reverse (3452403421), we get a palindrome (4695445964).

The spelling of 1243042543 in words is "one billion, two hundred forty-three million, forty-two thousand, five hundred forty-three".