6637649 has 2 divisors, whose sum is σ = 6637650. Its totient is φ = 6637648.

The previous prime is 6637643. The next prime is 6637651. The reversal of 6637649 is 9467366.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5607424 + 1030225 = 2368^2 + 1015^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6637649 is a prime.

It is a Sophie Germain prime.

Together with 6637651, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (6637643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3318824 + 3318825.

It is an arithmetic number, because the mean of its divisors is an integer number (3318825).

Almost surely, 2^6637649 is an apocalyptic number.

It is an amenable number.

6637649 is a deficient number, since it is larger than the sum of its proper divisors (1).

6637649 is an equidigital number, since it uses as much as digits as its factorization.

6637649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 41.

The square root of 6637649 is about 2576.3635224867. The cubic root of 6637649 is about 187.9337419294.

The spelling of 6637649 in words is "six million, six hundred thirty-seven thousand, six hundred forty-nine".