6640663380 has 96 divisors (see below), whose sum is σ = 20218808064. Its totient is φ = 1618735104.

The previous prime is 6640663373. The next prime is 6640663387. The reversal of 6640663380 is 833660466.

It is an interprime number because it is at equal distance from previous prime (6640663373) and next prime (6640663387).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640663387) by changing a digit.

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, 39012 + ... + 121668.

It is an arithmetic number, because the mean of its divisors is an integer number (210612584).

Almost surely, 2^6640663380 is an apocalyptic number.

6640663380 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 6640663380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10109404032).

6640663380 is an abundant number, since it is smaller than the sum of its proper divisors (13578144684).

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

6640663380 is a wasteful number, since it uses less digits than its factorization.

6640663380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82785 (or 82783 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 42.

The square root of 6640663380 is about 81490.2655536230. The cubic root of 6640663380 is about 1879.6218663817.

The spelling of 6640663380 in words is "six billion, six hundred forty million, six hundred sixty-three thousand, three hundred eighty".