6639697 has 2 divisors, whose sum is σ = 6639698. Its totient is φ = 6639696.

The previous prime is 6639679. The next prime is 6639719. The reversal of 6639697 is 7969366.

Together with previous prime (6639679) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4177936 + 2461761 = 2044^2 + 1569^2 .

It is a cyclic number.

It is not a de Polignac number, because 6639697 - 2¹¹ = 6637649 is a prime.

It is not a weakly prime, because it can be changed into another prime (6639497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3319848 + 3319849.

It is an arithmetic number, because the mean of its divisors is an integer number (3319849).

Almost surely, 2^6639697 is an apocalyptic number.

It is an amenable number.

6639697 is a deficient number, since it is larger than the sum of its proper divisors (1).

6639697 is an equidigital number, since it uses as much as digits as its factorization.

6639697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 46.

The square root of 6639697 is about 2576.7609512720. The cubic root of 6639697 is about 187.9530684874.

The spelling of 6639697 in words is "six million, six hundred thirty-nine thousand, six hundred ninety-seven".