165205320 has 256 divisors, whose sum is σ = 627056640. Its totient is φ = 33927168.

The previous prime is 165205319. The next prime is 165205321. The reversal of 165205320 is 23502561.

It is an interprime number because it is at equal distance from previous prime (165205319) and next prime (165205321).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (165205321) 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 63 ways as a sum of consecutive naturals, for example, 328189 + ... + 328691.

It is an arithmetic number, because the mean of its divisors is an integer number (2449440).

Almost surely, 2^165205320 is an apocalyptic number.

165205320 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 165205320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313528320).

165205320 is an abundant number, since it is smaller than the sum of its proper divisors (461851320).

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

165205320 is a wasteful number, since it uses less digits than its factorization.

165205320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564 (or 560 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 165205320 is about 12853.2221641112. Note that the first 3 decimals coincide. The cubic root of 165205320 is about 548.7080640704.

Adding to 165205320 its reverse (23502561), we get a palindrome (188707881).

The spelling of 165205320 in words is "one hundred sixty-five million, two hundred five thousand, three hundred twenty".