165641323 has 4 divisors (see below), whose sum is σ = 166257360. Its totient is φ = 165025288.

The previous prime is 165641321. The next prime is 165641327. The reversal of 165641323 is 323146561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 323146561 = 67 ⋅4823083.

It is a cyclic number.

It is not a de Polignac number, because 165641323 - 2¹ = 165641321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165641321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 307615 + ... + 308152.

It is an arithmetic number, because the mean of its divisors is an integer number (41564340).

Almost surely, 2^165641323 is an apocalyptic number.

165641323 is a deficient number, since it is larger than the sum of its proper divisors (616037).

165641323 is an equidigital number, since it uses as much as digits as its factorization.

165641323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616036.

The product of its digits is 12960, while the sum is 31.

The square root of 165641323 is about 12870.1718325747. The cubic root of 165641323 is about 549.1903492000.

Adding to 165641323 its reverse (323146561), we get a palindrome (488787884).

The spelling of 165641323 in words is "one hundred sixty-five million, six hundred forty-one thousand, three hundred twenty-three".