6643390 has 24 divisors (see below), whose sum is σ = 12952008. Its totient is φ = 2452320.

The previous prime is 6643381. The next prime is 6643411. The reversal of 6643390 is 933466.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 276 + ... + 3655.

It is an arithmetic number, because the mean of its divisors is an integer number (539667).

Almost surely, 2^6643390 is an apocalyptic number.

6643390 is a deficient number, since it is larger than the sum of its proper divisors (6308618).

6643390 is a wasteful number, since it uses less digits than its factorization.

6643390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3964 (or 3951 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 31.

The square root of 6643390 is about 2577.4774489799. The cubic root of 6643390 is about 187.9879085327.

The spelling of 6643390 in words is "six million, six hundred forty-three thousand, three hundred ninety".