6640287 has 8 divisors (see below), whose sum is σ = 8865840. Its totient is φ = 4420800.

The previous prime is 6640241. The next prime is 6640289. The reversal of 6640287 is 7820466.

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

It is not a de Polignac number, because 6640287 - 2⁶ = 6640223 is a prime.

It is a super-2 number, since 2×6640287² = 88186822884738, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2787 + ... + 4587.

It is an arithmetic number, because the mean of its divisors is an integer number (1108230).

Almost surely, 2^6640287 is an apocalyptic number.

6640287 is a deficient number, since it is larger than the sum of its proper divisors (2225553).

6640287 is a wasteful number, since it uses less digits than its factorization.

6640287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3033.

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 6640287 is about 2576.8754335435. The cubic root of 6640287 is about 187.9586354596.

The spelling of 6640287 in words is "six million, six hundred forty thousand, two hundred eighty-seven".