1666989732870 has 576 divisors, whose sum is σ = 5924402415360. Its totient is φ = 320517388800.

The previous prime is 1666989732869. The next prime is 1666989732893. The reversal of 1666989732870 is 782379896661.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 39611640 + ... + 39653700.

It is an arithmetic number, because the mean of its divisors is an integer number (10285420860).

Almost surely, 2^{1666989732870} is an apocalyptic number.

1666989732870 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666989732870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2962201207680).

1666989732870 is an abundant number, since it is smaller than the sum of its proper divisors (4257412682490).

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

1666989732870 is a wasteful number, since it uses less digits than its factorization.

1666989732870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42161 (or 42151 counting only the distinct ones).

The product of its (nonzero) digits is 329204736, while the sum is 72.

The spelling of 1666989732870 in words is "one trillion, six hundred sixty-six billion, nine hundred eighty-nine million, seven hundred thirty-two thousand, eight hundred seventy".