6640858632440 has 64 divisors (see below), whose sum is σ = 15547767212160. Its totient is φ = 2550772157440.

The previous prime is 6640858632433. The next prime is 6640858632449. The reversal of 6640858632440 is 442368580466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640858632449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33224621 + ... + 33423900.

It is an arithmetic number, because the mean of its divisors is an integer number (242933862690).

Almost surely, 2^{6640858632440} is an apocalyptic number.

It is an amenable number.

6640858632440 is an abundant number, since it is smaller than the sum of its proper divisors (8906908579720).

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

6640858632440 is a wasteful number, since it uses less digits than its factorization.

6640858632440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66648632 (or 66648628 counting only the distinct ones).

The product of its (nonzero) digits is 26542080, while the sum is 56.

The spelling of 6640858632440 in words is "six trillion, six hundred forty billion, eight hundred fifty-eight million, six hundred thirty-two thousand, four hundred forty".