129813 has 4 divisors (see below), whose sum is σ = 173088. Its totient is φ = 86540.

The previous prime is 129803. The next prime is 129841. The reversal of 129813 is 318921.

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: 318921 = 3 ⋅106307.

It is a cyclic number.

It is not a de Polignac number, because 129813 - 2⁶ = 129749 is a prime.

It is a D-number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21633 + ... + 21638.

It is an arithmetic number, because the mean of its divisors is an integer number (43272).

2¹²⁹⁸¹³ is an apocalyptic number.

It is an amenable number.

129813 is a deficient number, since it is larger than the sum of its proper divisors (43275).

129813 is an equidigital number, since it uses as much as digits as its factorization.

129813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43274.

The product of its digits is 432, while the sum is 24.

The square root of 129813 is about 360.2957118812. The cubic root of 129813 is about 50.6336686878.

The spelling of 129813 in words is "one hundred twenty-nine thousand, eight hundred thirteen".