6421866 has 16 divisors (see below), whose sum is σ = 14011488. Its totient is φ = 1946000.

The previous prime is 6421843. The next prime is 6421873. The reversal of 6421866 is 6681246.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48585 + ... + 48716.

It is an arithmetic number, because the mean of its divisors is an integer number (875718).

Almost surely, 2^6421866 is an apocalyptic number.

6421866 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

6421866 is an abundant number, since it is smaller than the sum of its proper divisors (7589622).

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

6421866 is a wasteful number, since it uses less digits than its factorization.

6421866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97317.

The product of its digits is 13824, while the sum is 33.

The square root of 6421866 is about 2534.1400908395. The cubic root of 6421866 is about 185.8747567083.

The spelling of 6421866 in words is "six million, four hundred twenty-one thousand, eight hundred sixty-six".