6639646 has 8 divisors (see below), whose sum is σ = 10725624. Its totient is φ = 3064440.

The previous prime is 6639641. The next prime is 6639653. The reversal of 6639646 is 6469366.

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

It is a junction number, because it is equal to n+sod(n) for n = 6639599 and 6639608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6639641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127660 + ... + 127711.

It is an arithmetic number, because the mean of its divisors is an integer number (1340703).

Almost surely, 2^6639646 is an apocalyptic number.

6639646 is a deficient number, since it is larger than the sum of its proper divisors (4085978).

6639646 is a wasteful number, since it uses less digits than its factorization.

6639646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255386.

The product of its digits is 139968, while the sum is 40.

The square root of 6639646 is about 2576.7510551080. The cubic root of 6639646 is about 187.9525872591.

The spelling of 6639646 in words is "six million, six hundred thirty-nine thousand, six hundred forty-six".