1666343003556 has 192 divisors, whose sum is σ = 4894764005376. Its totient is φ = 428619340800.

The previous prime is 1666343003489. The next prime is 1666343003581. The reversal of 1666343003556 is 6553003436661.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 42302286 + ... + 42341658.

It is an arithmetic number, because the mean of its divisors is an integer number (25493562528).

Almost surely, 2^{1666343003556} 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 1666343003556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2447382002688).

1666343003556 is an abundant number, since it is smaller than the sum of its proper divisors (3228421001820).

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

1666343003556 is a wasteful number, since it uses less digits than its factorization.

1666343003556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39842 (or 39840 counting only the distinct ones).

The product of its (nonzero) digits is 3499200, while the sum is 48.

The spelling of 1666343003556 in words is "one trillion, six hundred sixty-six billion, three hundred forty-three million, three thousand, five hundred fifty-six".