165668220 has 192 divisors, whose sum is σ = 552921600. Its totient is φ = 41057280.

The previous prime is 165668219. The next prime is 165668263. The reversal of 165668220 is 22866561.

165668220 is a `hidden beast` number, since 16 + 566 + 82 + 2 + 0 = 666.

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 (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 687300 + ... + 687540.

It is an arithmetic number, because the mean of its divisors is an integer number (2879800).

Almost surely, 2^165668220 is an apocalyptic number.

165668220 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 165668220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276460800).

165668220 is an abundant number, since it is smaller than the sum of its proper divisors (387253380).

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

165668220 is a wasteful number, since it uses less digits than its factorization.

165668220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345 (or 337 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 165668220 is about 12871.2167257024. The cubic root of 165668220 is about 549.2200736131.

The spelling of 165668220 in words is "one hundred sixty-five million, six hundred sixty-eight thousand, two hundred twenty".