664535243 has 2 divisors, whose sum is σ = 664535244. Its totient is φ = 664535242.

The previous prime is 664535237. The next prime is 664535269. The reversal of 664535243 is 342535466.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664535243 - 2¹⁰ = 664534219 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 664535197 and 664535206.

It is not a weakly prime, because it can be changed into another prime (664535213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332267621 + 332267622.

It is an arithmetic number, because the mean of its divisors is an integer number (332267622).

Almost surely, 2^664535243 is an apocalyptic number.

664535243 is a deficient number, since it is larger than the sum of its proper divisors (1).

664535243 is an equidigital number, since it uses as much as digits as its factorization.

664535243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 259200, while the sum is 38.

The square root of 664535243 is about 25778.5810897342. The cubic root of 664535243 is about 872.6484857699.

The spelling of 664535243 in words is "six hundred sixty-four million, five hundred thirty-five thousand, two hundred forty-three".