165567091 has 4 divisors (see below), whose sum is σ = 165960784. Its totient is φ = 165173400.

The previous prime is 165567049. The next prime is 165567107. The reversal of 165567091 is 190765561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165567091 - 2¹⁵ = 165534323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165567991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196215 + ... + 197056.

It is an arithmetic number, because the mean of its divisors is an integer number (41490196).

Almost surely, 2^165567091 is an apocalyptic number.

165567091 is a deficient number, since it is larger than the sum of its proper divisors (393693).

165567091 is an equidigital number, since it uses as much as digits as its factorization.

165567091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393692.

The product of its (nonzero) digits is 56700, while the sum is 40.

The square root of 165567091 is about 12867.2876318205. The cubic root of 165567091 is about 549.1082972322.

The spelling of 165567091 in words is "one hundred sixty-five million, five hundred sixty-seven thousand, ninety-one".