6447664 has 20 divisors (see below), whose sum is σ = 12652960. Its totient is φ = 3182400.

The previous prime is 6447653. The next prime is 6447671. The reversal of 6447664 is 4667446.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1287 + ... + 3814.

It is an arithmetic number, because the mean of its divisors is an integer number (632648).

Almost surely, 2^6447664 is an apocalyptic number.

It is an amenable number.

6447664 is a deficient number, since it is larger than the sum of its proper divisors (6205296).

6447664 is a wasteful number, since it uses less digits than its factorization.

6447664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5188 (or 5182 counting only the distinct ones).

The product of its digits is 96768, while the sum is 37.

The square root of 6447664 is about 2539.2250786411. The cubic root of 6447664 is about 186.1233236180.

The spelling of 6447664 in words is "six million, four hundred forty-seven thousand, six hundred sixty-four".