165530820 has 288 divisors, whose sum is σ = 598461696. Its totient is φ = 33868800.

The previous prime is 165530797. The next prime is 165530821. The reversal of 165530820 is 28035561.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165530821) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2331385 + ... + 2331455.

It is an arithmetic number, because the mean of its divisors is an integer number (2077992).

Almost surely, 2^165530820 is an apocalyptic number.

165530820 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 165530820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299230848).

165530820 is an abundant number, since it is smaller than the sum of its proper divisors (432930876).

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

165530820 is a wasteful number, since it uses less digits than its factorization.

165530820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 165530820 is about 12865.8781278232. The cubic root of 165530820 is about 549.0681963452.

The spelling of 165530820 in words is "one hundred sixty-five million, five hundred thirty thousand, eight hundred twenty".