165171091 has 2 divisors, whose sum is σ = 165171092. Its totient is φ = 165171090.

The previous prime is 165171089. The next prime is 165171107. The reversal of 165171091 is 190171561.

It is a weak prime.

It is an emirp because it is prime and its reverse (190171561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165171091 - 2¹ = 165171089 is a prime.

Together with 165171089, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (165171491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82585545 + 82585546.

It is an arithmetic number, because the mean of its divisors is an integer number (82585546).

Almost surely, 2^165171091 is an apocalyptic number.

165171091 is a deficient number, since it is larger than the sum of its proper divisors (1).

165171091 is an equidigital number, since it uses as much as digits as its factorization.

165171091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1890, while the sum is 31.

The square root of 165171091 is about 12851.8905613143. The cubic root of 165171091 is about 548.6701657235.

The spelling of 165171091 in words is "one hundred sixty-five million, one hundred seventy-one thousand, ninety-one".