129835891 has 4 divisors (see below), whose sum is σ = 129909784. Its totient is φ = 129762000.

The previous prime is 129835861. The next prime is 129835903. The reversal of 129835891 is 198538921.

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 129835891 - 2⁷ = 129835763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129835801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34245 + ... + 37846.

It is an arithmetic number, because the mean of its divisors is an integer number (32477446).

Almost surely, 2^129835891 is an apocalyptic number.

129835891 is a deficient number, since it is larger than the sum of its proper divisors (73893).

129835891 is an equidigital number, since it uses as much as digits as its factorization.

129835891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73892.

The product of its digits is 155520, while the sum is 46.

The square root of 129835891 is about 11394.5553226091. Note that the first 3 decimals coincide. The cubic root of 129835891 is about 506.3664473072.

The spelling of 129835891 in words is "one hundred twenty-nine million, eight hundred thirty-five thousand, eight hundred ninety-one".