6639281 has 8 divisors (see below), whose sum is σ = 7345728. Its totient is φ = 5950000.

The previous prime is 6639263. The next prime is 6639287. The reversal of 6639281 is 1829366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6639281 - 2¹⁴ = 6622897 is a prime.

It is a super-2 number, since 2×6639281² = 88160104393922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6639287) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3470 + ... + 5031.

It is an arithmetic number, because the mean of its divisors is an integer number (918216).

Almost surely, 2^6639281 is an apocalyptic number.

It is an amenable number.

6639281 is a deficient number, since it is larger than the sum of its proper divisors (706447).

6639281 is a wasteful number, since it uses less digits than its factorization.

6639281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8583.

The product of its digits is 15552, while the sum is 35.

The square root of 6639281 is about 2576.6802285111. The cubic root of 6639281 is about 187.9491431020.

The spelling of 6639281 in words is "six million, six hundred thirty-nine thousand, two hundred eighty-one".