165780 has 48 divisors (see below), whose sum is σ = 517440. Its totient is φ = 44064.

The previous prime is 165779. The next prime is 165799. The reversal of 165780 is 87561.

165780 is a `hidden beast` number, since 1 + 657 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 387 + ... + 693.

It is an arithmetic number, because the mean of its divisors is an integer number (10780).

2¹⁶⁵⁷⁸⁰ is an apocalyptic number.

165780 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 165780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258720).

165780 is an abundant number, since it is smaller than the sum of its proper divisors (351660).

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

165780 is a wasteful number, since it uses less digits than its factorization.

165780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 165780 is about 407.1609018558. The cubic root of 165780 is about 54.9343569472.

The spelling of 165780 in words is "one hundred sixty-five thousand, seven hundred eighty".