165122509 has 2 divisors, whose sum is σ = 165122510. Its totient is φ = 165122508.

The previous prime is 165122473. The next prime is 165122519. The reversal of 165122509 is 905221561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165122500 + 9 = 12850^2 + 3^2 .

It is an emirp because it is prime and its reverse (905221561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165122509 - 2⁷ = 165122381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165122519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82561254 + 82561255.

It is an arithmetic number, because the mean of its divisors is an integer number (82561255).

Almost surely, 2^165122509 is an apocalyptic number.

It is an amenable number.

165122509 is a deficient number, since it is larger than the sum of its proper divisors (1).

165122509 is an equidigital number, since it uses as much as digits as its factorization.

165122509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 165122509 is about 12850.0003501945. Note that the first 3 decimals coincide. The cubic root of 165122509 is about 548.6163667452.

The spelling of 165122509 in words is "one hundred sixty-five million, one hundred twenty-two thousand, five hundred nine".