6447989 has 2 divisors, whose sum is σ = 6447990. Its totient is φ = 6447988.

The previous prime is 6447983. The next prime is 6447997. The reversal of 6447989 is 9897446.

6447989 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., 6400900 + 47089 = 2530^2 + 217^2 .

It is a cyclic number.

It is not a de Polignac number, because 6447989 - 2⁸ = 6447733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6447983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3223994 + 3223995.

It is an arithmetic number, because the mean of its divisors is an integer number (3223995).

Almost surely, 2^6447989 is an apocalyptic number.

It is an amenable number.

6447989 is a deficient number, since it is larger than the sum of its proper divisors (1).

6447989 is an equidigital number, since it uses as much as digits as its factorization.

6447989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 47.

The square root of 6447989 is about 2539.2890737370. The cubic root of 6447989 is about 186.1264508004.

The spelling of 6447989 in words is "six million, four hundred forty-seven thousand, nine hundred eighty-nine".