6639842 has 16 divisors (see below), whose sum is σ = 10949472. Its totient is φ = 2994720.

The previous prime is 6639839. The next prime is 6639851. The reversal of 6639842 is 2489366.

It is a d-powerful number, because it can be written as 6 + 6⁸ + 3¹¹ + 9⁷ + 8 + 4³ + 2⁵ .

It is a junction number, because it is equal to n+sod(n) for n = 6639796 and 6639805.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1913 + ... + 4115.

It is an arithmetic number, because the mean of its divisors is an integer number (684342).

Almost surely, 2^6639842 is an apocalyptic number.

6639842 is a deficient number, since it is larger than the sum of its proper divisors (4309630).

6639842 is a wasteful number, since it uses less digits than its factorization.

6639842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2353.

The product of its digits is 62208, while the sum is 38.

The square root of 6639842 is about 2576.7890872169. The cubic root of 6639842 is about 187.9544366721.

The spelling of 6639842 in words is "six million, six hundred thirty-nine thousand, eight hundred forty-two".