6639169 has 4 divisors (see below), whose sum is σ = 6818644. Its totient is φ = 6459696.

The previous prime is 6639119. The next prime is 6639209. The reversal of 6639169 is 9619366.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9619366 = 2 ⋅4809683.

It can be written as a sum of positive squares in 2 ways, for example, as 3168400 + 3470769 = 1780^2 + 1863^2 .

It is a cyclic number.

It is not a de Polignac number, because 6639169 - 2⁷ = 6639041 is a prime.

It is a super-2 number, since 2×6639169² = 88157130021122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6639109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89682 + ... + 89755.

It is an arithmetic number, because the mean of its divisors is an integer number (1704661).

Almost surely, 2^6639169 is an apocalyptic number.

It is an amenable number.

6639169 is a deficient number, since it is larger than the sum of its proper divisors (179475).

6639169 is a wasteful number, since it uses less digits than its factorization.

6639169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179474.

The product of its digits is 52488, while the sum is 40.

The square root of 6639169 is about 2576.6584950280. The cubic root of 6639169 is about 187.9480862394.

The spelling of 6639169 in words is "six million, six hundred thirty-nine thousand, one hundred sixty-nine".