6664939 has 2 divisors, whose sum is σ = 6664940. Its totient is φ = 6664938.

The previous prime is 6664937. The next prime is 6664951. The reversal of 6664939 is 9394666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6664939 - 2¹ = 6664937 is a prime.

Together with 6664937, it forms a pair of twin primes.

6664939 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 6664895 and 6664904.

It is not a weakly prime, because it can be changed into another prime (6664937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3332469 + 3332470.

It is an arithmetic number, because the mean of its divisors is an integer number (3332470).

Almost surely, 2^6664939 is an apocalyptic number.

6664939 is a deficient number, since it is larger than the sum of its proper divisors (1).

6664939 is an equidigital number, since it uses as much as digits as its factorization.

6664939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 43.

The square root of 6664939 is about 2581.6543145820. The cubic root of 6664939 is about 188.1909464058.

The spelling of 6664939 in words is "six million, six hundred sixty-four thousand, nine hundred thirty-nine".