6481665116640 has 144 divisors (see below), whose sum is σ = 25278493994208. Its totient is φ = 1481523452928.

The previous prime is 6481665116621. The next prime is 6481665116671. The reversal of 6481665116640 is 466115661846.

6481665116640 is a `hidden beast` number, since 6 + 4 + 8 + 1 + 66 + 511 + 6 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 321501087 + ... + 321521246.

It is an arithmetic number, because the mean of its divisors is an integer number (175545097182).

Almost surely, 2^{6481665116640} is an apocalyptic number.

6481665116640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6481665116640 is an abundant number, since it is smaller than the sum of its proper divisors (18796828877568).

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

6481665116640 is a wasteful number, since it uses less digits than its factorization.

6481665116640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643022361 (or 643022350 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 54.

The spelling of 6481665116640 in words is "six trillion, four hundred eighty-one billion, six hundred sixty-five million, one hundred sixteen thousand, six hundred forty".