1666768320000 has 2400 divisors, whose sum is σ = 7461419581440. Its totient is φ = 365783040000.

The previous prime is 1666768319911. The next prime is 1666768320001. The reversal of 1666768320000 is 238676661.

It is a tau number, because it is divible by the number of its divisors (2400).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666768320001) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 13124159937 + ... + 13124160063.

Almost surely, 2^{1666768320000} is an apocalyptic number.

1666768320000 is a gapful number since it is divisible by the number (10) 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 1666768320000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3730709790720).

1666768320000 is an abundant number, since it is smaller than the sum of its proper divisors (5794651261440).

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

1666768320000 is an equidigital number, since it uses as much as digits as its factorization.

1666768320000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 1666768320000 in words is "one trillion, six hundred sixty-six billion, seven hundred sixty-eight million, three hundred twenty thousand".