165564 has 60 divisors (see below), whose sum is σ = 501424. Its totient is φ = 46656.

The previous prime is 165559. The next prime is 165569. The reversal of 165564 is 465561.

It is a happy number.

165564 is a `hidden beast` number, since 1 + 655 + 6 + 4 = 666.

165564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (165559) and next prime (165569).

It is a super-2 number, since 2×165564² = 54822876192, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165569) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2232 + ... + 2304.

2¹⁶⁵⁵⁶⁴ is an apocalyptic number.

165564 is a gapful number since it is divisible by the number (14) 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 165564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250712).

165564 is an abundant number, since it is smaller than the sum of its proper divisors (335860).

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

165564 is a wasteful number, since it uses less digits than its factorization.

165564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 85 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 165564 is about 406.8955639965. The cubic root of 165564 is about 54.9104880079.

It can be divided in two parts, 165 and 564, that added together give a 6-th power (729 = 3⁶).

The spelling of 165564 in words is "one hundred sixty-five thousand, five hundred sixty-four".