166309920 has 216 divisors, whose sum is σ = 660471084. Its totient is φ = 37997568.

The previous prime is 166309889. The next prime is 166309999. The reversal of 166309920 is 29903661.

166309920 is a `hidden beast` number, since 16 + 630 + 9 + 9 + 2 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 156650256 + 9659664 = 12516^2 + 3108^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 69382 + ... + 71738.

Almost surely, 2^166309920 is an apocalyptic number.

166309920 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 166309920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330235542).

166309920 is an abundant number, since it is smaller than the sum of its proper divisors (494161164).

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

166309920 is a wasteful number, since it uses less digits than its factorization.

166309920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2392 (or 2374 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 166309920 is about 12896.1203468330. The cubic root of 166309920 is about 549.9282771488.

The spelling of 166309920 in words is "one hundred sixty-six million, three hundred nine thousand, nine hundred twenty".