166566660 has 96 divisors (see below), whose sum is σ = 505491840. Its totient is φ = 40737792.

The previous prime is 166566643. The next prime is 166566677. The reversal of 166566660 is 66665661.

166566660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (166566643) and next prime (166566677).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139024 + ... + 140216.

It is an arithmetic number, because the mean of its divisors is an integer number (5265540).

Almost surely, 2^166566660 is an apocalyptic number.

166566660 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 166566660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252745920).

166566660 is an abundant number, since it is smaller than the sum of its proper divisors (338925180).

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

166566660 is a wasteful number, since it uses less digits than its factorization.

166566660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1397 (or 1395 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 42.

The square root of 166566660 is about 12906.0706646136. The cubic root of 166566660 is about 550.2111145467.

Subtracting from 166566660 its reverse (66665661), we obtain a palindrome (99900999).

The spelling of 166566660 in words is "one hundred sixty-six million, five hundred sixty-six thousand, six hundred sixty".