6438749 has 2 divisors, whose sum is σ = 6438750. Its totient is φ = 6438748.

The previous prime is 6438721. The next prime is 6438799. The reversal of 6438749 is 9478346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5244100 + 1194649 = 2290^2 + 1093^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6438749 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 (6438799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3219374 + 3219375.

It is an arithmetic number, because the mean of its divisors is an integer number (3219375).

Almost surely, 2^6438749 is an apocalyptic number.

It is an amenable number.

6438749 is a deficient number, since it is larger than the sum of its proper divisors (1).

6438749 is an equidigital number, since it uses as much as digits as its factorization.

6438749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 41.

The square root of 6438749 is about 2537.4690145891. The cubic root of 6438749 is about 186.0375015916.

The spelling of 6438749 in words is "six million, four hundred thirty-eight thousand, seven hundred forty-nine".