6447 has 8 divisors (see below), whose sum is σ = 9856. Its totient is φ = 3672.

The previous prime is 6427. The next prime is 6449. The reversal of 6447 is 7446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6447 - 2¹² = 2351 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 307 = 6447 / (6 + 4 + 4 + 7).

6447 is a lucky number.

It is a plaindrome in base 8.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133 + ... + 174.

It is an arithmetic number, because the mean of its divisors is an integer number (1232).

2⁶⁴⁴⁷ is an apocalyptic number.

6447 is a deficient number, since it is larger than the sum of its proper divisors (3409).

6447 is a wasteful number, since it uses less digits than its factorization.

6447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317.

The product of its digits is 672, while the sum is 21.

The square root of 6447 is about 80.2932126646. The cubic root of 6447 is about 18.6116934217.

Subtracting from 6447 its product of digits (672), we obtain a palindrome (5775).

Subtracting 6447 from its reverse (7446), we obtain a palindrome (999).

It can be divided in two parts, 64 and 47, that added together give a palindrome (111).

The spelling of 6447 in words is "six thousand, four hundred forty-seven".