6856840 has 64 divisors (see below), whose sum is σ = 16374960. Its totient is φ = 2580480.

The previous prime is 6856819. The next prime is 6856841. The reversal of 6856840 is 486586.

It can be written as a sum of positive squares in 8 ways, for example, as 736164 + 6120676 = 858^2 + 2474^2 .

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a self number, because there is not a number n which added to its sum of digits gives 6856840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6856841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60624 + ... + 60736.

Almost surely, 2^6856840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6856840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8187480).

6856840 is an abundant number, since it is smaller than the sum of its proper divisors (9518120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6856840 is a wasteful number, since it uses less digits than its factorization.

6856840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 6856840 is about 2618.5568544525. The cubic root of 6856840 is about 189.9800533077.

The spelling of 6856840 in words is "six million, eight hundred fifty-six thousand, eight hundred forty".