666203543 has 2 divisors, whose sum is σ = 666203544. Its totient is φ = 666203542.

The previous prime is 666203501. The next prime is 666203561. The reversal of 666203543 is 345302666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666203543 - 2¹⁰ = 666202519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666203563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333101771 + 333101772.

It is an arithmetic number, because the mean of its divisors is an integer number (333101772).

Almost surely, 2^666203543 is an apocalyptic number.

666203543 is a deficient number, since it is larger than the sum of its proper divisors (1).

666203543 is an equidigital number, since it uses as much as digits as its factorization.

666203543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 35.

The square root of 666203543 is about 25810.9190653878. The cubic root of 666203543 is about 873.3781299821.

The spelling of 666203543 in words is "six hundred sixty-six million, two hundred three thousand, five hundred forty-three".