129961 has 6 divisors (see below), whose sum is σ = 140910. Its totient is φ = 119808.

The previous prime is 129959. The next prime is 129967. The reversal of 129961 is 169921.

It can be written as a sum of positive squares in 3 ways, for example, as 361 + 129600 = 19^2 + 360^2 .

It is not a de Polignac number, because 129961 - 2¹ = 129959 is a prime.

It is the 361-st Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129967) by changing a digit.

It is a nontrivial repunit in base 360.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 216 + ... + 553.

It is an arithmetic number, because the mean of its divisors is an integer number (23485).

2¹²⁹⁹⁶¹ is an apocalyptic number.

It is an amenable number.

129961 is a deficient number, since it is larger than the sum of its proper divisors (10949).

129961 is an equidigital number, since it uses as much as digits as its factorization.

129961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795 (or 782 counting only the distinct ones).

The product of its digits is 972, while the sum is 28.

The square root of 129961 is about 360.5010402204. The cubic root of 129961 is about 50.6529038873.

The spelling of 129961 in words is "one hundred twenty-nine thousand, nine hundred sixty-one".