6645216 has 24 divisors (see below), whose sum is σ = 17443944. Its totient is φ = 2215040.

The previous prime is 6645211. The next prime is 6645217. The reversal of 6645216 is 6125466.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6645211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34515 + ... + 34706.

It is an arithmetic number, because the mean of its divisors is an integer number (726831).

Almost surely, 2^6645216 is an apocalyptic number.

It is an amenable number.

6645216 is an abundant number, since it is smaller than the sum of its proper divisors (10798728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6645216 is a wasteful number, since it uses less digits than its factorization.

6645216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69234 (or 69226 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 6645216 is about 2577.8316469467. The cubic root of 6645216 is about 188.0051303866.

The spelling of 6645216 in words is "six million, six hundred forty-five thousand, two hundred sixteen".