6638549 has 2 divisors, whose sum is σ = 6638550. Its totient is φ = 6638548.

The previous prime is 6638531. The next prime is 6638579. The reversal of 6638549 is 9458366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6027025 + 611524 = 2455^2 + 782^2 .

It is a cyclic number.

It is not a de Polignac number, because 6638549 - 2²⁰ = 5589973 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6638509) 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, 3319274 + 3319275.

It is an arithmetic number, because the mean of its divisors is an integer number (3319275).

Almost surely, 2^6638549 is an apocalyptic number.

It is an amenable number.

6638549 is a deficient number, since it is larger than the sum of its proper divisors (1).

6638549 is an equidigital number, since it uses as much as digits as its factorization.

6638549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 41.

The square root of 6638549 is about 2576.5381813589. The cubic root of 6638549 is about 187.9422355353.

The spelling of 6638549 in words is "six million, six hundred thirty-eight thousand, five hundred forty-nine".