1666123457700 has 576 divisors, whose sum is σ = 5541545318400. Its totient is φ = 383110041600.

The previous prime is 1666123457693. The next prime is 1666123457749. The reversal of 1666123457700 is 77543216661.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1666123457700.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3197933440 + ... + 3197933960.

It is an arithmetic number, because the mean of its divisors is an integer number (9620738400).

Almost surely, 2^{1666123457700} is an apocalyptic number.

1666123457700 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 1666123457700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2770772659200).

1666123457700 is an abundant number, since it is smaller than the sum of its proper divisors (3875421860700).

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

1666123457700 is a wasteful number, since it uses less digits than its factorization.

1666123457700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092 (or 1085 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 48.

The spelling of 1666123457700 in words is "one trillion, six hundred sixty-six billion, one hundred twenty-three million, four hundred fifty-seven thousand, seven hundred".