6639009 has 8 divisors (see below), whose sum is σ = 9532992. Its totient is φ = 4085520.

The previous prime is 6639001. The next prime is 6639011. The reversal of 6639009 is 9009366.

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

It is not a de Polignac number, because 6639009 - 2³ = 6639001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6639001) by changing a digit.

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, 85077 + ... + 85154.

It is an arithmetic number, because the mean of its divisors is an integer number (1191624).

Almost surely, 2^6639009 is an apocalyptic number.

It is an amenable number.

6639009 is a deficient number, since it is larger than the sum of its proper divisors (2893983).

6639009 is a wasteful number, since it uses less digits than its factorization.

6639009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170247.

The product of its (nonzero) digits is 8748, while the sum is 33.

The square root of 6639009 is about 2576.6274468770. The cubic root of 6639009 is about 187.9465764152.

Subtracting from 6639009 its product of nonzero digits (8748), we obtain a triangular number (6630261 = T₃₆₄₁).

It can be divided in two parts, 6 and 639009, that added together give a triangular number (639015 = T₁₁₃₀).

The spelling of 6639009 in words is "six million, six hundred thirty-nine thousand, nine".