6640331656 has 128 divisors (see below), whose sum is σ = 15199027200. Its totient is φ = 2658458880.

The previous prime is 6640331629. The next prime is 6640331701. The reversal of 6640331656 is 6561330466.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17520475 + ... + 17520853.

It is an arithmetic number, because the mean of its divisors is an integer number (118742400).

Almost surely, 2^6640331656 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 6640331656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7599513600).

6640331656 is an abundant number, since it is smaller than the sum of its proper divisors (8558695544).

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

6640331656 is a wasteful number, since it uses less digits than its factorization.

6640331656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699 (or 695 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 40.

The square root of 6640331656 is about 81488.2301685342. The cubic root of 6640331656 is about 1879.5905679993.

The spelling of 6640331656 in words is "six billion, six hundred forty million, three hundred thirty-one thousand, six hundred fifty-six".