129805305 has 64 divisors (see below), whose sum is σ = 251043840. Its totient is φ = 56012544.

The previous prime is 129805279. The next prime is 129805309. The reversal of 129805305 is 503508921.

It is not a de Polignac number, because 129805305 - 2⁶ = 129805241 is a prime.

It is a super-2 number, since 2×129805305² = 33698834412286050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129805309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 142662 + ... + 143568.

It is an arithmetic number, because the mean of its divisors is an integer number (3922560).

Almost surely, 2^129805305 is an apocalyptic number.

129805305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129805305 is a deficient number, since it is larger than the sum of its proper divisors (121238535).

129805305 is a wasteful number, since it uses less digits than its factorization.

129805305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 998.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 129805305 is about 11393.2131113220. The cubic root of 129805305 is about 506.3266818762.

The spelling of 129805305 in words is "one hundred twenty-nine million, eight hundred five thousand, three hundred five".