6646909438 has 16 divisors (see below), whose sum is σ = 10919306160. Its totient is φ = 3015806976.

The previous prime is 6646909433. The next prime is 6646909447. The reversal of 6646909438 is 8349096466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6646909433) 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, 2164995 + ... + 2168062.

It is an arithmetic number, because the mean of its divisors is an integer number (682456635).

Almost surely, 2^6646909438 is an apocalyptic number.

6646909438 is a deficient number, since it is larger than the sum of its proper divisors (4272396722).

6646909438 is a wasteful number, since it uses less digits than its factorization.

6646909438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4333131.

The product of its (nonzero) digits is 6718464, while the sum is 55.

The square root of 6646909438 is about 81528.5804978843. The cubic root of 6646909438 is about 1880.2109916735.

The spelling of 6646909438 in words is "six billion, six hundred forty-six million, nine hundred nine thousand, four hundred thirty-eight".