6680521 has 2 divisors, whose sum is σ = 6680522. Its totient is φ = 6680520.

The previous prime is 6680519. The next prime is 6680539. The reversal of 6680521 is 1250866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5588496 + 1092025 = 2364^2 + 1045^2 .

It is a cyclic number.

It is not a de Polignac number, because 6680521 - 2¹ = 6680519 is a prime.

Together with 6680519, it forms a pair of twin primes.

6680521 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6680521.

It is not a weakly prime, because it can be changed into another prime (6680551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3340260 + 3340261.

It is an arithmetic number, because the mean of its divisors is an integer number (3340261).

Almost surely, 2^6680521 is an apocalyptic number.

It is an amenable number.

6680521 is a deficient number, since it is larger than the sum of its proper divisors (1).

6680521 is an equidigital number, since it uses as much as digits as its factorization.

6680521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 6680521 is about 2584.6703851749. The cubic root of 6680521 is about 188.3374898361.

The spelling of 6680521 in words is "six million, six hundred eighty thousand, five hundred twenty-one".