129181389 has 4 divisors (see below), whose sum is σ = 172241856. Its totient is φ = 86120924.

The previous prime is 129181369. The next prime is 129181391. The reversal of 129181389 is 983181921.

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.

It is a cyclic number.

It is not a de Polignac number, because 129181389 - 2²³ = 120792781 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129181389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129181369) 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, 21530229 + ... + 21530234.

It is an arithmetic number, because the mean of its divisors is an integer number (43060464).

Almost surely, 2^129181389 is an apocalyptic number.

It is an amenable number.

129181389 is a deficient number, since it is larger than the sum of its proper divisors (43060467).

129181389 is an equidigital number, since it uses as much as digits as its factorization.

129181389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43060466.

The product of its digits is 31104, while the sum is 42.

The square root of 129181389 is about 11365.7990920128. The cubic root of 129181389 is about 505.5141500812.

The spelling of 129181389 in words is "one hundred twenty-nine million, one hundred eighty-one thousand, three hundred eighty-nine".