6440549 has 2 divisors, whose sum is σ = 6440550. Its totient is φ = 6440548.

The previous prime is 6440543. The next prime is 6440561. The reversal of 6440549 is 9450446.

It is a happy number.

6440549 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3928324 + 2512225 = 1982^2 + 1585^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6440549 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6440543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3220274 + 3220275.

It is an arithmetic number, because the mean of its divisors is an integer number (3220275).

Almost surely, 2^6440549 is an apocalyptic number.

It is an amenable number.

6440549 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440549 is an equidigital number, since it uses as much as digits as its factorization.

6440549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 6440549 is about 2537.8236739380. The cubic root of 6440549 is about 186.0548360305.

The spelling of 6440549 in words is "six million, four hundred forty thousand, five hundred forty-nine".