6640144 has 40 divisors (see below), whose sum is σ = 14874048. Its totient is φ = 2812800.

The previous prime is 6640129. The next prime is 6640157. The reversal of 6640144 is 4410466.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11019 + ... + 11605.

Almost surely, 2^6640144 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 6640144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7437024).

6640144 is an abundant number, since it is smaller than the sum of its proper divisors (8233904).

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

6640144 is a wasteful number, since it uses less digits than its factorization.

6640144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 703 (or 697 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 6640144 is about 2576.8476866125. The cubic root of 6640144 is about 187.9572862068.

The spelling of 6640144 in words is "six million, six hundred forty thousand, one hundred forty-four".