6639479289 has 27 divisors (see below), whose sum is σ = 9707946573. Its totient is φ = 4372703712.

The previous prime is 6639479267. The next prime is 6639479311. The reversal of 6639479289 is 9829749366.

The square root of 6639479289 is 81483.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (6639479267) and next prime (6639479311).

It can be written as a sum of positive squares in 4 ways, for example, as 461519289 + 6177960000 = 21483^2 + 78600^2 .

It is not a de Polignac number, because 6639479289 - 2¹¹ = 6639477241 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6639479089) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 38378407 + ... + 38378579.

Almost surely, 2^6639479289 is an apocalyptic number.

6639479289 is the 81483-rd square number.

6639479289 is the 40742-nd centered octagonal number.

It is an amenable number.

6639479289 is a deficient number, since it is larger than the sum of its proper divisors (3068467284).

6639479289 is an equidigital number, since it uses as much as digits as its factorization.

6639479289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666 (or 333 counting only the distinct ones).

The product of its digits is 35271936, while the sum is 63.

The cubic root of 6639479289 is about 1879.5101418192.

The spelling of 6639479289 in words is "six billion, six hundred thirty-nine million, four hundred seventy-nine thousand, two hundred eighty-nine".