6639490 has 32 divisors (see below), whose sum is σ = 14043456. Its totient is φ = 2228160.

The previous prime is 6639481. The next prime is 6639497. The reversal of 6639490 is 949366.

It is not an unprimeable number, because it can be changed into a prime (6639497) 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 15 ways as a sum of consecutive naturals, for example, 892 + ... + 3751.

It is an arithmetic number, because the mean of its divisors is an integer number (438858).

Almost surely, 2^6639490 is an apocalyptic number.

6639490 is an abundant number, since it is smaller than the sum of its proper divisors (7403966).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6639490 is a wasteful number, since it uses less digits than its factorization.

6639490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4674.

The product of its (nonzero) digits is 34992, while the sum is 37.

The square root of 6639490 is about 2576.7207842527. The cubic root of 6639490 is about 187.9511152512.

It can be divided in two parts, 663 and 9490, that added together give a triangular number (10153 = T₁₄₂).

The spelling of 6639490 in words is "six million, six hundred thirty-nine thousand, four hundred ninety".