6661994965648 has 160 divisors (see below), whose sum is σ = 14594449895424. Its totient is φ = 2918583360000.

The previous prime is 6661994965643. The next prime is 6661994965663. The reversal of 6661994965648 is 8465694991666.

It is a super-3 number, since 3×6661994965648³ (a number of 39 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (6661994965643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3111626658 + ... + 3111628798.

Almost surely, 2^{6661994965648} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6661994965648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7297224947712).

6661994965648 is an abundant number, since it is smaller than the sum of its proper divisors (7932454929776).

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

6661994965648 is a wasteful number, since it uses less digits than its factorization.

6661994965648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4245 (or 4239 counting only the distinct ones).

The product of its digits is 3627970560, while the sum is 79.

The spelling of 6661994965648 in words is "six trillion, six hundred sixty-one billion, nine hundred ninety-four million, nine hundred sixty-five thousand, six hundred forty-eight".