6656540 has 48 divisors (see below), whose sum is σ = 15482880. Its totient is φ = 2383680.

The previous prime is 6656539. The next prime is 6656543. The reversal of 6656540 is 456566.

It is a junction number, because it is equal to n+sod(n) for n = 6656497 and 6656506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6656543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17189 + ... + 17571.

It is an arithmetic number, because the mean of its divisors is an integer number (322560).

Almost surely, 2^6656540 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 6656540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7741440).

6656540 is an abundant number, since it is smaller than the sum of its proper divisors (8826340).

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

6656540 is a wasteful number, since it uses less digits than its factorization.

6656540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 482 (or 480 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 6656540 is about 2580.0271316403. The cubic root of 6656540 is about 188.1118619023. Note that the first 3 decimals are identical.

The spelling of 6656540 in words is "six million, six hundred fifty-six thousand, five hundred forty".