165887999 has 4 divisors (see below), whose sum is σ = 168699720. Its totient is φ = 163076280.

The previous prime is 165887977. The next prime is 165888011. The reversal of 165887999 is 999788561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999788561 = 10883 ⋅91867.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165887999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165887699) 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, 1405772 + ... + 1405889.

It is an arithmetic number, because the mean of its divisors is an integer number (42174930).

Almost surely, 2^165887999 is an apocalyptic number.

165887999 is a deficient number, since it is larger than the sum of its proper divisors (2811721).

165887999 is an equidigital number, since it uses as much as digits as its factorization.

165887999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2811720.

The product of its digits is 9797760, while the sum is 62.

The square root of 165887999 is about 12879.7515115782. The cubic root of 165887999 is about 549.4628353215.

The spelling of 165887999 in words is "one hundred sixty-five million, eight hundred eighty-seven thousand, nine hundred ninety-nine".