1666494720000 has 720 divisors, whose sum is σ = 6561775059840. Its totient is φ = 403968000000.

The previous prime is 1666494719987. The next prime is 1666494720029. The reversal of 1666494720000 is 274946661.

It is a tau number, because it is divible by the number of its divisors (720).

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 59 ways as a sum of consecutive naturals, for example, 126713425 + ... + 126726575.

It is an arithmetic number, because the mean of its divisors is an integer number (9113576472).

Almost surely, 2^{1666494720000} is an apocalyptic number.

1666494720000 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 1666494720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3280887529920).

1666494720000 is an abundant number, since it is smaller than the sum of its proper divisors (4895280339840).

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

1666494720000 is a wasteful number, since it uses less digits than its factorization.

1666494720000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13210 (or 13172 counting only the distinct ones).

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

The spelling of 1666494720000 in words is "one trillion, six hundred sixty-six billion, four hundred ninety-four million, seven hundred twenty thousand".