6640135212 has 12 divisors (see below), whose sum is σ = 15493648856. Its totient is φ = 2213378400.

The previous prime is 6640135171. The next prime is 6640135217. The reversal of 6640135212 is 2125310466.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 6640135212.

It is not an unprimeable number, because it can be changed into a prime (6640135217) 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, 276672289 + ... + 276672312.

Almost surely, 2^6640135212 is an apocalyptic number.

It is an amenable number.

6640135212 is an abundant number, since it is smaller than the sum of its proper divisors (8853513644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6640135212 is a wasteful number, since it uses less digits than its factorization.

6640135212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553344608 (or 553344606 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 6640135212 is about 81487.0248076343. The cubic root of 6640135212 is about 1879.5720328844.

Adding to 6640135212 its reverse (2125310466), we get a palindrome (8765445678).

The spelling of 6640135212 in words is "six billion, six hundred forty million, one hundred thirty-five thousand, two hundred twelve".