6639158 has 4 divisors (see below), whose sum is σ = 9958740. Its totient is φ = 3319578.

The previous prime is 6639119. The next prime is 6639209. The reversal of 6639158 is 8519366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8519366 = 2 ⋅4259683.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1659788 + ... + 1659791.

It is an arithmetic number, because the mean of its divisors is an integer number (2489685).

Almost surely, 2^6639158 is an apocalyptic number.

6639158 is a deficient number, since it is larger than the sum of its proper divisors (3319582).

6639158 is a wasteful number, since it uses less digits than its factorization.

6639158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3319581.

The product of its digits is 38880, while the sum is 38.

The square root of 6639158 is about 2576.6563604796. The cubic root of 6639158 is about 187.9479824398.

The spelling of 6639158 in words is "six million, six hundred thirty-nine thousand, one hundred fifty-eight".