165878 has 4 divisors (see below), whose sum is σ = 248820. Its totient is φ = 82938.

The previous prime is 165877. The next prime is 165883. The reversal of 165878 is 878561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 878561 = 397 ⋅2213.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41468 + ... + 41471.

It is an arithmetic number, because the mean of its divisors is an integer number (62205).

2¹⁶⁵⁸⁷⁸ is an apocalyptic number.

165878 is a deficient number, since it is larger than the sum of its proper divisors (82942).

165878 is an equidigital number, since it uses as much as digits as its factorization.

165878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82941.

The product of its digits is 13440, while the sum is 35.

The square root of 165878 is about 407.2812296190. The cubic root of 165878 is about 54.9451795364.

The spelling of 165878 in words is "one hundred sixty-five thousand, eight hundred seventy-eight".