165550220 has 48 divisors (see below), whose sum is σ = 381755808. Its totient is φ = 59804160.

The previous prime is 165550219. The next prime is 165550237. The reversal of 165550220 is 22055561.

It is a self number, because there is not a number n which added to its sum of digits gives 165550220.

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 15 ways as a sum of consecutive naturals, for example, 32144 + ... + 36936.

It is an arithmetic number, because the mean of its divisors is an integer number (7953246).

Almost surely, 2^165550220 is an apocalyptic number.

165550220 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 165550220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190877904).

165550220 is an abundant number, since it is smaller than the sum of its proper divisors (216205588).

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

165550220 is a wasteful number, since it uses less digits than its factorization.

165550220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4970 (or 4968 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 165550220 is about 12866.6320379499. The cubic root of 165550220 is about 549.0896455370.

The spelling of 165550220 in words is "one hundred sixty-five million, five hundred fifty thousand, two hundred twenty".