6640812 has 48 divisors (see below), whose sum is σ = 18234720. Its totient is φ = 2082816.

The previous prime is 6640807. The next prime is 6640817. The reversal of 6640812 is 2180466.

6640812 is a `hidden beast` number, since 6 + 640 + 8 + 12 = 666.

It is an interprime number because it is at equal distance from previous prime (6640807) and next prime (6640817).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (6640817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28 + ... + 3644.

It is an arithmetic number, because the mean of its divisors is an integer number (379890).

Almost surely, 2^6640812 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 6640812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9117360).

6640812 is an abundant number, since it is smaller than the sum of its proper divisors (11593908).

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

6640812 is a wasteful number, since it uses less digits than its factorization.

6640812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3647 (or 3639 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 6640812 is about 2576.9772990851. The cubic root of 6640812 is about 187.9635888441.

The spelling of 6640812 in words is "six million, six hundred forty thousand, eight hundred twelve".