6821856 has 36 divisors (see below), whose sum is σ = 19400472. Its totient is φ = 2273856.

The previous prime is 6821851. The next prime is 6821863. The reversal of 6821856 is 6581286.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 6821856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6821851) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11556 + ... + 12131.

It is an arithmetic number, because the mean of its divisors is an integer number (538902).

Almost surely, 2^6821856 is an apocalyptic number.

It is an amenable number.

6821856 is an abundant number, since it is smaller than the sum of its proper divisors (12578616).

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

6821856 is a wasteful number, since it uses less digits than its factorization.

6821856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23703 (or 23692 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 6821856 is about 2611.8682968327. The cubic root of 6821856 is about 189.6564057995.

The spelling of 6821856 in words is "six million, eight hundred twenty-one thousand, eight hundred fifty-six".