129205135 has 4 divisors (see below), whose sum is σ = 155046168. Its totient is φ = 103364104.

The previous prime is 129205129. The next prime is 129205171. The reversal of 129205135 is 531502921.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 129205135 - 2¹⁷ = 129074063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12920509 + ... + 12920518.

It is an arithmetic number, because the mean of its divisors is an integer number (38761542).

Almost surely, 2^129205135 is an apocalyptic number.

129205135 is a deficient number, since it is larger than the sum of its proper divisors (25841033).

129205135 is an equidigital number, since it uses as much as digits as its factorization.

129205135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25841032.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 129205135 is about 11366.8436691986. The cubic root of 129205135 is about 505.5451225602.

The spelling of 129205135 in words is "one hundred twenty-nine million, two hundred five thousand, one hundred thirty-five".