6636989 has 2 divisors, whose sum is σ = 6636990. Its totient is φ = 6636988.

The previous prime is 6636979. The next prime is 6637003. The reversal of 6636989 is 9896366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6416089 + 220900 = 2533^2 + 470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6636989 is a prime.

It is a super-2 number, since 2×6636989² = 88099245972242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6636979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3318494 + 3318495.

It is an arithmetic number, because the mean of its divisors is an integer number (3318495).

Almost surely, 2^6636989 is an apocalyptic number.

It is an amenable number.

6636989 is a deficient number, since it is larger than the sum of its proper divisors (1).

6636989 is an equidigital number, since it uses as much as digits as its factorization.

6636989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 47.

The square root of 6636989 is about 2576.2354317880. The cubic root of 6636989 is about 187.9275127971.

The spelling of 6636989 in words is "six million, six hundred thirty-six thousand, nine hundred eighty-nine".