165005491 has 24 divisors (see below), whose sum is σ = 199355904. Its totient is φ = 136074960.

The previous prime is 165005479. The next prime is 165005509. The reversal of 165005491 is 194500561.

It is not a de Polignac number, because 165005491 - 2⁷ = 165005363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165005891) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 149046 + ... + 150148.

It is an arithmetic number, because the mean of its divisors is an integer number (8306496).

Almost surely, 2^165005491 is an apocalyptic number.

165005491 is a deficient number, since it is larger than the sum of its proper divisors (34350413).

165005491 is a wasteful number, since it uses less digits than its factorization.

165005491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1231 (or 1224 counting only the distinct ones).

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

The square root of 165005491 is about 12845.4463137721. The cubic root of 165005491 is about 548.4867394329.

The spelling of 165005491 in words is "one hundred sixty-five million, five thousand, four hundred ninety-one".