6643540640610 has 96 divisors (see below), whose sum is σ = 18028292705280. Its totient is φ = 1694200869504.

The previous prime is 6643540640599. The next prime is 6643540640651. The reversal of 6643540640610 is 160460453466.

6643540640610 is a `hidden beast` number, since 6 + 6 + 4 + 3 + 540 + 6 + 40 + 61 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8844436 + ... + 9566144.

It is an arithmetic number, because the mean of its divisors is an integer number (187794715680).

Almost surely, 2^{6643540640610} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6643540640610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9014146352640).

6643540640610 is an abundant number, since it is smaller than the sum of its proper divisors (11384752064670).

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

6643540640610 is a wasteful number, since it uses less digits than its factorization.

6643540640610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726192 (or 726189 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 45.

The spelling of 6643540640610 in words is "six trillion, six hundred forty-three billion, five hundred forty million, six hundred forty thousand, six hundred ten".