664043543 has 2 divisors, whose sum is σ = 664043544. Its totient is φ = 664043542.

The previous prime is 664043533. The next prime is 664043563. The reversal of 664043543 is 345340466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664043543 - 2⁸ = 664043287 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664043533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332021771 + 332021772.

It is an arithmetic number, because the mean of its divisors is an integer number (332021772).

Almost surely, 2^664043543 is an apocalyptic number.

664043543 is a deficient number, since it is larger than the sum of its proper divisors (1).

664043543 is an equidigital number, since it uses as much as digits as its factorization.

664043543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 35.

The square root of 664043543 is about 25769.0423376578. The cubic root of 664043543 is about 872.4332039186.

The spelling of 664043543 in words is "six hundred sixty-four million, forty-three thousand, five hundred forty-three".