6391668 has 12 divisors (see below), whose sum is σ = 14913920. Its totient is φ = 2130552.

The previous prime is 6391667. The next prime is 6391669. The reversal of 6391668 is 8661936.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (6391667) and next prime (6391669).

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6391663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266308 + ... + 266331.

Almost surely, 2^6391668 is an apocalyptic number.

It is an amenable number.

6391668 is an abundant number, since it is smaller than the sum of its proper divisors (8522252).

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

6391668 is a wasteful number, since it uses less digits than its factorization.

6391668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 532646 (or 532644 counting only the distinct ones).

The product of its digits is 46656, while the sum is 39.

The square root of 6391668 is about 2528.1748357264. The cubic root of 6391668 is about 185.5829481089.

The spelling of 6391668 in words is "six million, three hundred ninety-one thousand, six hundred sixty-eight".