6391666 has 8 divisors (see below), whose sum is σ = 9730800. Its totient is φ = 3148068.

The previous prime is 6391663. The next prime is 6391667. The reversal of 6391666 is 6661936.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 23716 + ... + 23983.

It is an arithmetic number, because the mean of its divisors is an integer number (1216350).

Almost surely, 2^6391666 is an apocalyptic number.

6391666 is a deficient number, since it is larger than the sum of its proper divisors (3339134).

6391666 is a wasteful number, since it uses less digits than its factorization.

6391666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47768.

The product of its digits is 34992, while the sum is 37.

The square root of 6391666 is about 2528.1744401841. The cubic root of 6391666 is about 185.5829287521.

The spelling of 6391666 in words is "six million, three hundred ninety-one thousand, six hundred sixty-six".