6820640 has 48 divisors (see below), whose sum is σ = 16474752. Its totient is φ = 2667264.

The previous prime is 6820633. The next prime is 6820643. The reversal of 6820640 is 460286.

It is a super-2 number, since 2×6820640² = 93042260019200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6820643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7067 + ... + 7973.

It is an arithmetic number, because the mean of its divisors is an integer number (343224).

Almost surely, 2^6820640 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 6820640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8237376).

6820640 is an abundant number, since it is smaller than the sum of its proper divisors (9654112).

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

6820640 is a wasteful number, since it uses less digits than its factorization.

6820640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969 (or 961 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 6820640 is about 2611.6355028985. The cubic root of 6820640 is about 189.6451363398.

The spelling of 6820640 in words is "six million, eight hundred twenty thousand, six hundred forty".