6639242 has 4 divisors (see below), whose sum is σ = 9958866. Its totient is φ = 3319620.

The previous prime is 6639233. The next prime is 6639251. The reversal of 6639242 is 2429366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2429366 = 2 ⋅1214683.

It is an interprime number because it is at equal distance from previous prime (6639233) and next prime (6639251).

It can be written as a sum of positive squares in only one way, i.e., 6446521 + 192721 = 2539^2 + 439^2 .

It is a junction number, because it is equal to n+sod(n) for n = 6639199 and 6639208.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1659809 + ... + 1659812.

Almost surely, 2^6639242 is an apocalyptic number.

6639242 is a deficient number, since it is larger than the sum of its proper divisors (3319624).

6639242 is a wasteful number, since it uses less digits than its factorization.

6639242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3319623.

The product of its digits is 15552, while the sum is 32.

The square root of 6639242 is about 2576.6726606226. The cubic root of 6639242 is about 187.9487750887.

The spelling of 6639242 in words is "six million, six hundred thirty-nine thousand, two hundred forty-two".