6638669 has 2 divisors, whose sum is σ = 6638670. Its totient is φ = 6638668.

The previous prime is 6638647. The next prime is 6638689. The reversal of 6638669 is 9668366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5697769 + 940900 = 2387^2 + 970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6638669 is a prime.

It is a super-2 number, since 2×6638669² = 88143852183122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6638689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3319334 + 3319335.

It is an arithmetic number, because the mean of its divisors is an integer number (3319335).

Almost surely, 2^6638669 is an apocalyptic number.

It is an amenable number.

6638669 is a deficient number, since it is larger than the sum of its proper divisors (1).

6638669 is an equidigital number, since it uses as much as digits as its factorization.

6638669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 44.

The square root of 6638669 is about 2576.5614683139. The cubic root of 6638669 is about 187.9433679580.

The spelling of 6638669 in words is "six million, six hundred thirty-eight thousand, six hundred sixty-nine".