6840517 has 4 divisors (see below), whose sum is σ = 6853356. Its totient is φ = 6827680.

The previous prime is 6840497. The next prime is 6840527. The reversal of 6840517 is 7150486.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3207681 + 3632836 = 1791^2 + 1906^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6840517 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6840527) 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, 5584 + ... + 6697.

It is an arithmetic number, because the mean of its divisors is an integer number (1713339).

Almost surely, 2^6840517 is an apocalyptic number.

It is an amenable number.

6840517 is a deficient number, since it is larger than the sum of its proper divisors (12839).

6840517 is a wasteful number, since it uses less digits than its factorization.

6840517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12838.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 6840517 is about 2615.4382042021. The cubic root of 6840517 is about 189.8291816529.

Subtracting from 6840517 its sum of digits (31), we obtain a palindrome (6840486).

The spelling of 6840517 in words is "six million, eight hundred forty thousand, five hundred seventeen".