6661448640000 has 6400 divisors, whose sum is σ = 35343566438400. Its totient is φ = 1194393600000.

The previous prime is 6661448639977. The next prime is 6661448640013. The reversal of 6661448640000 is 468441666.

It is a tau number, because it is divible by the number of its divisors (6400).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 639 ways as a sum of consecutive naturals, for example, 214885439985 + ... + 214885440015.

It is an arithmetic number, because the mean of its divisors is an integer number (5522432256).

Almost surely, 2^{6661448640000} is an apocalyptic number.

6661448640000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6661448640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17671783219200).

6661448640000 is an abundant number, since it is smaller than the sum of its proper divisors (28682117798400).

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

6661448640000 is a wasteful number, since it uses less digits than its factorization.

6661448640000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The spelling of 6661448640000 in words is "six trillion, six hundred sixty-one billion, four hundred forty-eight million, six hundred forty thousand".