6640064 has 42 divisors (see below), whose sum is σ = 14036040. Its totient is φ = 3116032.

The previous prime is 6640061. The next prime is 6640069. The reversal of 6640064 is 4600466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640061) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18317 + ... + 18675.

Almost surely, 2^6640064 is an apocalyptic number.

6640064 is a gapful number since it is divisible by the number (64) 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 6640064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7018020).

6640064 is an abundant number, since it is smaller than the sum of its proper divisors (7395976).

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

6640064 is a wasteful number, since it uses less digits than its factorization.

6640064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 6640064 is about 2576.8321637235. The cubic root of 6640064 is about 187.9565313716.

The spelling of 6640064 in words is "six million, six hundred forty thousand, sixty-four".