166131388800 has 960 divisors, whose sum is σ = 674909928000. Its totient is φ = 39985643520.

The previous prime is 166131388747. The next prime is 166131388859. The reversal of 166131388800 is 8883131661.

166131388800 is a `hidden beast` number, since 1 + 66 + 131 + 388 + 80 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 158370676 + ... + 158371724.

It is an arithmetic number, because the mean of its divisors is an integer number (703031175).

Almost surely, 2^166131388800 is an apocalyptic number.

166131388800 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 166131388800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337454964000).

166131388800 is an abundant number, since it is smaller than the sum of its proper divisors (508778539200).

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

166131388800 is a wasteful number, since it uses less digits than its factorization.

166131388800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1145 (or 1119 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

It can be divided in two parts, 166131 and 388800, that added together give a triangular number (554931 = T₁₀₅₃).

The spelling of 166131388800 in words is "one hundred sixty-six billion, one hundred thirty-one million, three hundred eighty-eight thousand, eight hundred".