159561 has 6 divisors (see below), whose sum is σ = 230490. Its totient is φ = 106368.

The previous prime is 159553. The next prime is 159563. The reversal of 159561 is 165951.

It can be written as a sum of positive squares in only one way, i.e., 145161 + 14400 = 381^2 + 120^2 .

It is not a de Polignac number, because 159561 - 2³ = 159553 is a prime.

159561 is a lucky number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (159563) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8856 + ... + 8873.

It is an arithmetic number, because the mean of its divisors is an integer number (38415).

2¹⁵⁹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

159561 is a deficient number, since it is larger than the sum of its proper divisors (70929).

159561 is a wasteful number, since it uses less digits than its factorization.

159561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17735 (or 17732 counting only the distinct ones).

The product of its digits is 1350, while the sum is 27.

The square root of 159561 is about 399.4508730745. The cubic root of 159561 is about 54.2386556301.

The spelling of 159561 in words is "one hundred fifty-nine thousand, five hundred sixty-one".