6687641 has 4 divisors (see below), whose sum is σ = 6978432. Its totient is φ = 6396852.

The previous prime is 6687631. The next prime is 6687689. The reversal of 6687641 is 1467866.

6687641 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 de Polignac number, because none of the positive numbers 2^k-6687641 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6687595 and 6687604.

It is not an unprimeable number, because it can be changed into a prime (6687631) 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 3 ways as a sum of consecutive naturals, for example, 145361 + ... + 145406.

It is an arithmetic number, because the mean of its divisors is an integer number (1744608).

Almost surely, 2^6687641 is an apocalyptic number.

It is an amenable number.

6687641 is a deficient number, since it is larger than the sum of its proper divisors (290791).

6687641 is a wasteful number, since it uses less digits than its factorization.

6687641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290790.

The product of its digits is 48384, while the sum is 38.

The square root of 6687641 is about 2586.0473700224. The cubic root of 6687641 is about 188.4043751792.

The spelling of 6687641 in words is "six million, six hundred eighty-seven thousand, six hundred forty-one".