159221 has 4 divisors (see below), whose sum is σ = 161100. Its totient is φ = 157344.

The previous prime is 159209. The next prime is 159223. The reversal of 159221 is 122951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122951 = 37 ⋅3323.

It can be written as a sum of positive squares in 2 ways, for example, as 96721 + 62500 = 311^2 + 250^2 .

It is a cyclic number.

It is not a de Polignac number, because 159221 - 2⁶ = 159157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 159193 and 159202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (159223) 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, 806 + ... + 983.

It is an arithmetic number, because the mean of its divisors is an integer number (40275).

2¹⁵⁹²²¹ is an apocalyptic number.

It is an amenable number.

159221 is a deficient number, since it is larger than the sum of its proper divisors (1879).

159221 is an equidigital number, since it uses as much as digits as its factorization.

159221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1878.

The product of its digits is 180, while the sum is 20.

The square root of 159221 is about 399.0250618696. The cubic root of 159221 is about 54.2001034842.

Subtracting from 159221 its sum of digits (20), we obtain a square (159201 = 399²).

The spelling of 159221 in words is "one hundred fifty-nine thousand, two hundred twenty-one".