6664643 has 2 divisors, whose sum is σ = 6664644. Its totient is φ = 6664642.

The previous prime is 6664631. The next prime is 6664657. The reversal of 6664643 is 3464666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6664643 - 2⁸ = 6664387 is a prime.

It is not a weakly prime, because it can be changed into another prime (6664543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3332321 + 3332322.

It is an arithmetic number, because the mean of its divisors is an integer number (3332322).

Almost surely, 2^6664643 is an apocalyptic number.

6664643 is a deficient number, since it is larger than the sum of its proper divisors (1).

6664643 is an equidigital number, since it uses as much as digits as its factorization.

6664643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 35.

The square root of 6664643 is about 2581.5969863633. The cubic root of 6664643 is about 188.1881604166.

The spelling of 6664643 in words is "six million, six hundred sixty-four thousand, six hundred forty-three".