6643320 has 128 divisors (see below), whose sum is σ = 21772800. Its totient is φ = 1616384.

The previous prime is 6643319. The next prime is 6643321. The reversal of 6643320 is 233466.

It is an interprime number because it is at equal distance from previous prime (6643319) and next prime (6643321).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79999 + ... + 80081.

It is an arithmetic number, because the mean of its divisors is an integer number (170100).

Almost surely, 2^6643320 is an apocalyptic number.

6643320 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6643320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10886400).

6643320 is an abundant number, since it is smaller than the sum of its proper divisors (15129480).

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

6643320 is a wasteful number, since it uses less digits than its factorization.

6643320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149 (or 145 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 24.

The square root of 6643320 is about 2577.4638697759. The cubic root of 6643320 is about 187.9872482674.

Adding to 6643320 its reverse (233466), we get a palindrome (6876786).

The spelling of 6643320 in words is "six million, six hundred forty-three thousand, three hundred twenty".