129773909 has 4 divisors (see below), whose sum is σ = 132535104. Its totient is φ = 127012716.

The previous prime is 129773879. The next prime is 129773953. The reversal of 129773909 is 909377921.

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 129773909 - 2⁸ = 129773653 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 2761147 = 129773909 / (1 + 2 + 9 + 7 + 7 + 3 + 9 + 0 + 9).

It is a Duffinian 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 (129773989) 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, 1380527 + ... + 1380620.

It is an arithmetic number, because the mean of its divisors is an integer number (33133776).

Almost surely, 2^129773909 is an apocalyptic number.

It is an amenable number.

129773909 is a deficient number, since it is larger than the sum of its proper divisors (2761195).

129773909 is an equidigital number, since it uses as much as digits as its factorization.

129773909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2761194.

The product of its (nonzero) digits is 214326, while the sum is 47.

The square root of 129773909 is about 11391.8351901702. The cubic root of 129773909 is about 506.2858568516.

The spelling of 129773909 in words is "one hundred twenty-nine million, seven hundred seventy-three thousand, nine hundred nine".