6639449369 has 4 divisors (see below), whose sum is σ = 7587942144. Its totient is φ = 5690956596.

The previous prime is 6639449359. The next prime is 6639449371. The reversal of 6639449369 is 9639449366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6639449369 - 2²⁴ = 6622672153 is a prime.

It is a super-2 number, since 2×6639449369² = 88164575847028996322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6639449359) 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, 474246377 + ... + 474246390.

It is an arithmetic number, because the mean of its divisors is an integer number (1896985536).

Almost surely, 2^6639449369 is an apocalyptic number.

It is an amenable number.

6639449369 is a deficient number, since it is larger than the sum of its proper divisors (948492775).

6639449369 is an equidigital number, since it uses as much as digits as its factorization.

6639449369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 948492774.

The product of its digits is 22674816, while the sum is 59.

The square root of 6639449369 is about 81482.8164032147. The cubic root of 6639449369 is about 1879.5073185542.

The spelling of 6639449369 in words is "six billion, six hundred thirty-nine million, four hundred forty-nine thousand, three hundred sixty-nine".