6687321 has 4 divisors (see below), whose sum is σ = 8916432. Its totient is φ = 4458212.

The previous prime is 6687293. The next prime is 6687323. The reversal of 6687321 is 1237866.

6687321 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6687321 is a prime.

It is a D-number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6687323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1114551 + ... + 1114556.

It is an arithmetic number, because the mean of its divisors is an integer number (2229108).

Almost surely, 2^6687321 is an apocalyptic number.

It is an amenable number.

6687321 is a deficient number, since it is larger than the sum of its proper divisors (2229111).

6687321 is a wasteful number, since it uses less digits than its factorization.

6687321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2229110.

The product of its digits is 12096, while the sum is 33.

The square root of 6687321 is about 2585.9854987992. The cubic root of 6687321 is about 188.4013701155.

The spelling of 6687321 in words is "six million, six hundred eighty-seven thousand, three hundred twenty-one".