165980 has 24 divisors (see below), whose sum is σ = 358512. Its totient is φ = 64512.

The previous prime is 165961. The next prime is 165983. The reversal of 165980 is 89561.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 764 + ... + 956.

It is an arithmetic number, because the mean of its divisors is an integer number (14938).

2¹⁶⁵⁹⁸⁰ is an apocalyptic number.

165980 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 165980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (179256).

165980 is an abundant number, since it is smaller than the sum of its proper divisors (192532).

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

165980 is a wasteful number, since it uses less digits than its factorization.

165980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 165980 is about 407.4064309753. The cubic root of 165980 is about 54.9564393377.

The spelling of 165980 in words is "one hundred sixty-five thousand, nine hundred eighty".