6689845 has 4 divisors (see below), whose sum is σ = 8027820. Its totient is φ = 5351872.

The previous prime is 6689821. The next prime is 6689869. The reversal of 6689845 is 5489866.

6689845 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 an emirpimes, since its reverse is a distinct semiprime: 5489866 = 2 ⋅2744933.

It is an interprime number because it is at equal distance from previous prime (6689821) and next prime (6689869).

It can be written as a sum of positive squares in 2 ways, for example, as 2745649 + 3944196 = 1657^2 + 1986^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6689845 is a prime.

It is a super-2 number, since 2×6689845² = 89508052248050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6689795 and 6689804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 668980 + ... + 668989.

It is an arithmetic number, because the mean of its divisors is an integer number (2006955).

Almost surely, 2^6689845 is an apocalyptic number.

It is an amenable number.

6689845 is a deficient number, since it is larger than the sum of its proper divisors (1337975).

6689845 is a wasteful number, since it uses less digits than its factorization.

6689845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1337974.

The product of its digits is 414720, while the sum is 46.

The square root of 6689845 is about 2586.4734678709. The cubic root of 6689845 is about 188.4250699521.

Adding to 6689845 its product of digits (414720), we get a triangular number (7104565 = T₃₇₆₉).

The spelling of 6689845 in words is "six million, six hundred eighty-nine thousand, eight hundred forty-five".