165649 has 9 divisors (see below), whose sum is σ = 187131.
Its totient is φ = 146520.
The previous prime is 165617. The next prime is 165653. The reversal of 165649 is 946561.
165649 = T406 + T407.
The square root of 165649 is 407.
It is a perfect power (a square), and thus also a powerful number.
It can be written as a sum of positive squares in only one way, i.e., 148225 + 17424 = 385^2 + 132^2
It is not a de Polignac number, because 165649 - 25 = 165617 is a prime.
It is a Duffinian number.
Its product of digits (6480) is a multiple of the sum of its prime divisors (48).
It is a self number, because there is not a number n which added to its sum of digits gives 165649.
It is not an unprimeable number, because it can be changed into a prime (165049) 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 8 ways as a sum of consecutive naturals, for example, 4459 + ... + 4495.
2165649 is an apocalyptic number.
165649 is the 407-th square number.
165649 is the 204-th centered octagonal number.
It is an amenable number.
165649 is a deficient number, since it is larger than the sum of its proper divisors (21482).
165649 is an equidigital number, since it uses as much as digits as its factorization.
165649 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 96 (or 48 counting only the distinct ones).
The product of its digits is 6480, while the sum is 31.
The cubic root of 165649 is about 54.9198833534.
It can be divided in two parts, 16 and 5649, that added together give a palindrome (5665).
The spelling of 165649 in words is "one hundred sixty-five thousand, six hundred forty-nine".