166721058 has 128 divisors (see below), whose sum is σ = 446515200. Its totient is φ = 45105984.

The previous prime is 166721011. The next prime is 166721077. The reversal of 166721058 is 850127661.

It is a super-2 number, since 2×166721058² = 55591822361278728, which contains 22 as substring.

It is a Curzon 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 63 ways as a sum of consecutive naturals, for example, 734341 + ... + 734567.

It is an arithmetic number, because the mean of its divisors is an integer number (3488400).

Almost surely, 2^166721058 is an apocalyptic number.

166721058 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 166721058, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (223257600).

166721058 is an abundant number, since it is smaller than the sum of its proper divisors (279794142).

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

166721058 is a wasteful number, since it uses less digits than its factorization.

166721058 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341 (or 335 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 166721058 is about 12912.0508827994. The cubic root of 166721058 is about 550.3810670465.

The spelling of 166721058 in words is "one hundred sixty-six million, seven hundred twenty-one thousand, fifty-eight".