166139172 has 72 divisors (see below), whose sum is σ = 432432000. Its totient is φ = 53755968.

The previous prime is 166139123. The next prime is 166139201. The reversal of 166139172 is 271931661.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 23 ways as a sum of consecutive naturals, for example, 251779 + ... + 252437.

It is an arithmetic number, because the mean of its divisors is an integer number (6006000).

Almost surely, 2^166139172 is an apocalyptic number.

166139172 is a gapful number since it is divisible by the number (12) 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 166139172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216216000).

166139172 is an abundant number, since it is smaller than the sum of its proper divisors (266292828).

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

166139172 is a wasteful number, since it uses less digits than its factorization.

166139172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865 (or 860 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 166139172 is about 12889.4985162341. The cubic root of 166139172 is about 549.7400115565.

The spelling of 166139172 in words is "one hundred sixty-six million, one hundred thirty-nine thousand, one hundred seventy-two".