165849409 has 16 divisors (see below), whose sum is σ = 185765184. Its totient is φ = 146764800.

The previous prime is 165849377. The next prime is 165849419. The reversal of 165849409 is 904948561.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 165849409 - 2⁵ = 165849377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165849419) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 246097 + ... + 246769.

It is an arithmetic number, because the mean of its divisors is an integer number (11610324).

Almost surely, 2^165849409 is an apocalyptic number.

It is an amenable number.

165849409 is a deficient number, since it is larger than the sum of its proper divisors (19915775).

165849409 is a wasteful number, since it uses less digits than its factorization.

165849409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248.

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 165849409 is about 12878.2533365360. The cubic root of 165849409 is about 549.4202254174.

The spelling of 165849409 in words is "one hundred sixty-five million, eight hundred forty-nine thousand, four hundred nine".