165522121 has 2 divisors, whose sum is σ = 165522122. Its totient is φ = 165522120.

The previous prime is 165522103. The next prime is 165522139. The reversal of 165522121 is 121225561.

It is a balanced prime because it is at equal distance from previous prime (165522103) and next prime (165522139).

It can be written as a sum of positive squares in only one way, i.e., 162282121 + 3240000 = 12739^2 + 1800^2 .

It is a cyclic number.

It is not a de Polignac number, because 165522121 - 2⁵ = 165522089 is a prime.

It is not a weakly prime, because it can be changed into another prime (165522101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82761060 + 82761061.

It is an arithmetic number, because the mean of its divisors is an integer number (82761061).

Almost surely, 2^165522121 is an apocalyptic number.

It is an amenable number.

165522121 is a deficient number, since it is larger than the sum of its proper divisors (1).

165522121 is an equidigital number, since it uses as much as digits as its factorization.

165522121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 25.

The square root of 165522121 is about 12865.5400586217. The cubic root of 165522121 is about 549.0585779392.

Adding to 165522121 its reverse (121225561), we get a palindrome (286747682).

The spelling of 165522121 in words is "one hundred sixty-five million, five hundred twenty-two thousand, one hundred twenty-one".