165210091 has 2 divisors, whose sum is σ = 165210092. Its totient is φ = 165210090.

The previous prime is 165210061. The next prime is 165210107. The reversal of 165210091 is 190012561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 165210091 - 2⁷ = 165209963 is a prime.

It is not a weakly prime, because it can be changed into another prime (165210011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82605045 + 82605046.

It is an arithmetic number, because the mean of its divisors is an integer number (82605046).

Almost surely, 2^165210091 is an apocalyptic number.

165210091 is a deficient number, since it is larger than the sum of its proper divisors (1).

165210091 is an equidigital number, since it uses as much as digits as its factorization.

165210091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 165210091 is about 12853.4077582562. The cubic root of 165210091 is about 548.7133461057.

The spelling of 165210091 in words is "one hundred sixty-five million, two hundred ten thousand, ninety-one".