165221065 has 8 divisors (see below), whose sum is σ = 198612360. Its totient is φ = 131945472.

The previous prime is 165221059. The next prime is 165221101. The reversal of 165221065 is 560122561.

It can be written as a sum of positive squares in 4 ways, for example, as 111007296 + 54213769 = 10536^2 + 7363^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165221065 - 2³ = 165221057 is a prime.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 25750 + ... + 31519.

It is an arithmetic number, because the mean of its divisors is an integer number (24826545).

Almost surely, 2^165221065 is an apocalyptic number.

It is an amenable number.

165221065 is a deficient number, since it is larger than the sum of its proper divisors (33391295).

165221065 is an equidigital number, since it uses as much as digits as its factorization.

165221065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57851.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 165221065 is about 12853.8346418491. The cubic root of 165221065 is about 548.7254951758.

The spelling of 165221065 in words is "one hundred sixty-five million, two hundred twenty-one thousand, sixty-five".