129206813 has 8 divisors (see below), whose sum is σ = 130824120. Its totient is φ = 127595520.

The previous prime is 129206797. The next prime is 129206837. The reversal of 129206813 is 318602921.

It can be written as a sum of positive squares in 4 ways, for example, as 8602489 + 120604324 = 2933^2 + 10982^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 129206813 - 2⁴ = 129206797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 129206813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129206863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54023 + ... + 56363.

It is an arithmetic number, because the mean of its divisors is an integer number (16353015).

Almost surely, 2^129206813 is an apocalyptic number.

It is an amenable number.

129206813 is a deficient number, since it is larger than the sum of its proper divisors (1617307).

129206813 is an equidigital number, since it uses as much as digits as its factorization.

129206813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3007.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 129206813 is about 11366.9174801263. The cubic root of 129206813 is about 505.5473110724.

The spelling of 129206813 in words is "one hundred twenty-nine million, two hundred six thousand, eight hundred thirteen".