6639907 has 2 divisors, whose sum is σ = 6639908. Its totient is φ = 6639906.

The previous prime is 6639889. The next prime is 6639929. The reversal of 6639907 is 7099366.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6639907 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6639907.

It is not a weakly prime, because it can be changed into another prime (6639937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3319953 + 3319954.

It is an arithmetic number, because the mean of its divisors is an integer number (3319954).

Almost surely, 2^6639907 is an apocalyptic number.

6639907 is a deficient number, since it is larger than the sum of its proper divisors (1).

6639907 is an equidigital number, since it uses as much as digits as its factorization.

6639907 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61236, while the sum is 40.

The square root of 6639907 is about 2576.8016997821. The cubic root of 6639907 is about 187.9550499899.

The spelling of 6639907 in words is "six million, six hundred thirty-nine thousand, nine hundred seven".