6686390 has 16 divisors (see below), whose sum is σ = 12424320. Its totient is φ = 2588160.

The previous prime is 6686363. The next prime is 6686413. The reversal of 6686390 is 936866.

It is a happy number.

It is a super-2 number, since 2×6686390² = 89415622464200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 10475 + ... + 11094.

It is an arithmetic number, because the mean of its divisors is an integer number (776520).

Almost surely, 2^6686390 is an apocalyptic number.

6686390 is a deficient number, since it is larger than the sum of its proper divisors (5737930).

6686390 is a wasteful number, since it uses less digits than its factorization.

6686390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21607.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 6686390 is about 2585.8054837903. The cubic root of 6686390 is about 188.3926267131.

The spelling of 6686390 in words is "six million, six hundred eighty-six thousand, three hundred ninety".