129881 has 4 divisors (see below), whose sum is σ = 135552. Its totient is φ = 124212.

The previous prime is 129853. The next prime is 129887. The reversal of 129881 is 188921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 188921 = 17 ⋅11113.

It is a cyclic number.

It is not a de Polignac number, because 129881 - 2¹⁰ = 128857 is a prime.

It is a super-2 number, since 2×129881² = 33738148322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129887) 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, 2801 + ... + 2846.

It is an arithmetic number, because the mean of its divisors is an integer number (33888).

2¹²⁹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

129881 is a deficient number, since it is larger than the sum of its proper divisors (5671).

129881 is an equidigital number, since it uses as much as digits as its factorization.

129881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5670.

The product of its digits is 1152, while the sum is 29.

The square root of 129881 is about 360.3900664558. The cubic root of 129881 is about 50.6425082967.

The spelling of 129881 in words is "one hundred twenty-nine thousand, eight hundred eighty-one".