664445543 has 2 divisors, whose sum is σ = 664445544. Its totient is φ = 664445542.

The previous prime is 664445513. The next prime is 664445557. The reversal of 664445543 is 345544466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664445543 - 2¹⁴ = 664429159 is a prime.

It is a super-2 number, since 2×664445543² = 882975759225129698, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 664445543.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664445513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332222771 + 332222772.

It is an arithmetic number, because the mean of its divisors is an integer number (332222772).

Almost surely, 2^664445543 is an apocalyptic number.

664445543 is a deficient number, since it is larger than the sum of its proper divisors (1).

664445543 is an equidigital number, since it uses as much as digits as its factorization.

664445543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 691200, while the sum is 41.

The square root of 664445543 is about 25776.8412145476. The cubic root of 664445543 is about 872.6092201868.

The spelling of 664445543 in words is "six hundred sixty-four million, four hundred forty-five thousand, five hundred forty-three".