6646 has 4 divisors (see below), whose sum is σ = 9972. Its totient is φ = 3322.

The previous prime is 6637. The next prime is 6653. The reversal of 6646 is 6466.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1660 + ... + 1663.

It is an arithmetic number, because the mean of its divisors is an integer number (2493).

2⁶⁶⁴⁶ is an apocalyptic number.

6646 is a deficient number, since it is larger than the sum of its proper divisors (3326).

6646 is a wasteful number, since it uses less digits than its factorization.

6646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3325.

The product of its digits is 864, while the sum is 22.

The square root of 6646 is about 81.5230028888. The cubic root of 6646 is about 18.8012523687.

The spelling of 6646 in words is "six thousand, six hundred forty-six".