159905 has 4 divisors (see below), whose sum is σ = 191892. Its totient is φ = 127920.

The previous prime is 159899. The next prime is 159911. The reversal of 159905 is 509951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 509951 = 13 ⋅39227.

It is an interprime number because it is at equal distance from previous prime (159899) and next prime (159911).

It can be written as a sum of positive squares in 2 ways, for example, as 29584 + 130321 = 172^2 + 361^2 .

It is not a de Polignac number, because 159905 - 2¹⁰ = 158881 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15986 + ... + 15995.

It is an arithmetic number, because the mean of its divisors is an integer number (47973).

2¹⁵⁹⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

159905 is a deficient number, since it is larger than the sum of its proper divisors (31987).

159905 is an equidigital number, since it uses as much as digits as its factorization.

159905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31986.

The product of its (nonzero) digits is 2025, while the sum is 29.

The square root of 159905 is about 399.8812323678. The cubic root of 159905 is about 54.2776056349.

The spelling of 159905 in words is "one hundred fifty-nine thousand, nine hundred five".