129775809 has 8 divisors (see below), whose sum is σ = 174748032. Its totient is φ = 85660400.

The previous prime is 129775801. The next prime is 129775819. The reversal of 129775809 is 908577921.

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 129775809 - 2³ = 129775801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129775801) 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, 213849 + ... + 214454.

It is an arithmetic number, because the mean of its divisors is an integer number (21843504).

Almost surely, 2^129775809 is an apocalyptic number.

It is an amenable number.

129775809 is a deficient number, since it is larger than the sum of its proper divisors (44972223).

129775809 is a wasteful number, since it uses less digits than its factorization.

129775809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428407.

The product of its (nonzero) digits is 317520, while the sum is 48.

The square root of 129775809 is about 11391.9185829254. The cubic root of 129775809 is about 506.2883276575.

The spelling of 129775809 in words is "one hundred twenty-nine million, seven hundred seventy-five thousand, eight hundred nine".