165025321 has 2 divisors, whose sum is σ = 165025322. Its totient is φ = 165025320.

The previous prime is 165025309. The next prime is 165025339. The reversal of 165025321 is 123520561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105349696 + 59675625 = 10264^2 + 7725^2 .

It is a cyclic number.

It is not a de Polignac number, because 165025321 - 2²¹ = 162928169 is a prime.

It is not a weakly prime, because it can be changed into another prime (165020321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82512660 + 82512661.

It is an arithmetic number, because the mean of its divisors is an integer number (82512661).

Almost surely, 2^165025321 is an apocalyptic number.

It is an amenable number.

165025321 is a deficient number, since it is larger than the sum of its proper divisors (1).

165025321 is an equidigital number, since it uses as much as digits as its factorization.

165025321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 165025321 is about 12846.2181594429. The cubic root of 165025321 is about 548.5087105328.

Adding to 165025321 its reverse (123520561), we get a palindrome (288545882).

The spelling of 165025321 in words is "one hundred sixty-five million, twenty-five thousand, three hundred twenty-one".