6421856 has 24 divisors (see below), whose sum is σ = 14449680. Its totient is φ = 2752128.

The previous prime is 6421843. The next prime is 6421873. The reversal of 6421856 is 6581246.

It is a Harshad number since it is a multiple of its sum of digits (32).

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, 14111 + ... + 14558.

It is an arithmetic number, because the mean of its divisors is an integer number (602070).

Almost surely, 2^6421856 is an apocalyptic number.

It is an amenable number.

6421856 is an abundant number, since it is smaller than the sum of its proper divisors (8027824).

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

6421856 is a wasteful number, since it uses less digits than its factorization.

6421856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28686 (or 28678 counting only the distinct ones).

The product of its digits is 11520, while the sum is 32.

The square root of 6421856 is about 2534.1381177828. The cubic root of 6421856 is about 185.8746602281.

The spelling of 6421856 in words is "six million, four hundred twenty-one thousand, eight hundred fifty-six".