165844913 has 4 divisors (see below), whose sum is σ = 178602228. Its totient is φ = 153087600.

The previous prime is 165844871. The next prime is 165844919. The reversal of 165844913 is 319448561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 319448561 = 127 ⋅2515343.

It can be written as a sum of positive squares in 2 ways, for example, as 8392609 + 157452304 = 2897^2 + 12548^2 .

It is a cyclic number.

It is not a de Polignac number, because 165844913 - 2⁶ = 165844849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165844919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6378638 + ... + 6378663.

It is an arithmetic number, because the mean of its divisors is an integer number (44650557).

Almost surely, 2^165844913 is an apocalyptic number.

165844913 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

165844913 is a deficient number, since it is larger than the sum of its proper divisors (12757315).

165844913 is a wasteful number, since it uses less digits than its factorization.

165844913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12757314.

The product of its digits is 103680, while the sum is 41.

The square root of 165844913 is about 12878.0787775196. The cubic root of 165844913 is about 549.4152606410.

The spelling of 165844913 in words is "one hundred sixty-five million, eight hundred forty-four thousand, nine hundred thirteen".