6644664 has 96 divisors (see below), whose sum is σ = 20092800. Its totient is φ = 1969920.

The previous prime is 6644647. The next prime is 6644681. The reversal of 6644664 is 4664466.

It is a happy number.

6644664 is a `hidden beast` number, since 6 + 644 + 6 + 6 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (6644647) and next prime (6644681).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28902 + ... + 29130.

It is an arithmetic number, because the mean of its divisors is an integer number (209300).

Almost surely, 2^6644664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6644664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10046400).

6644664 is an abundant number, since it is smaller than the sum of its proper divisors (13448136).

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

6644664 is a wasteful number, since it uses less digits than its factorization.

6644664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285 (or 278 counting only the distinct ones).

The product of its digits is 82944, while the sum is 36.

The square root of 6644664 is about 2577.7245779951. The cubic root of 6644664 is about 187.9999245510. Note that the first 4 decimals are identical.

The spelling of 6644664 in words is "six million, six hundred forty-four thousand, six hundred sixty-four".