165212161 has 2 divisors, whose sum is σ = 165212162. Its totient is φ = 165212160.

The previous prime is 165212153. The next prime is 165212207. The reversal of 165212161 is 161212561.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164634561 + 577600 = 12831^2 + 760^2 .

It is an emirp because it is prime and its reverse (161212561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165212161 - 2³ = 165212153 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (165212111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82606080 + 82606081.

It is an arithmetic number, because the mean of its divisors is an integer number (82606081).

Almost surely, 2^165212161 is an apocalyptic number.

It is an amenable number.

165212161 is a deficient number, since it is larger than the sum of its proper divisors (1).

165212161 is an equidigital number, since it uses as much as digits as its factorization.

165212161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 25.

The square root of 165212161 is about 12853.4882813966. The cubic root of 165212161 is about 548.7156377976.

The spelling of 165212161 in words is "one hundred sixty-five million, two hundred twelve thousand, one hundred sixty-one".