166021856 has 192 divisors, whose sum is σ = 451132416. Its totient is φ = 58060800.

The previous prime is 166021853. The next prime is 166021859. The reversal of 166021856 is 658120661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (166021853) and next prime (166021859).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166021853) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 2274236 + ... + 2274308.

It is an arithmetic number, because the mean of its divisors is an integer number (2349648).

Almost surely, 2^166021856 is an apocalyptic number.

166021856 is a gapful number since it is divisible by the number (16) 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 166021856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225566208).

166021856 is an abundant number, since it is smaller than the sum of its proper divisors (285110560).

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

166021856 is a wasteful number, since it uses less digits than its factorization.

166021856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 177 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 166021856 is about 12884.9468761031. The cubic root of 166021856 is about 549.6105849546.

The spelling of 166021856 in words is "one hundred sixty-six million, twenty-one thousand, eight hundred fifty-six".