6440686 has 16 divisors (see below), whose sum is σ = 11096064. Its totient is φ = 2746584.

The previous prime is 6440683. The next prime is 6440699. The reversal of 6440686 is 6860446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2091 + ... + 4153.

It is an arithmetic number, because the mean of its divisors is an integer number (693504).

Almost surely, 2^6440686 is an apocalyptic number.

6440686 is a deficient number, since it is larger than the sum of its proper divisors (4655378).

6440686 is a wasteful number, since it uses less digits than its factorization.

6440686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2295.

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 6440686 is about 2537.8506654254. The cubic root of 6440686 is about 186.0561552416.

The spelling of 6440686 in words is "six million, four hundred forty thousand, six hundred eighty-six".