129268509 has 4 divisors (see below), whose sum is σ = 172358016. Its totient is φ = 86179004.

The previous prime is 129268507. The next prime is 129268511. The reversal of 129268509 is 905862921.

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 an interprime number because it is at equal distance from previous prime (129268507) and next prime (129268511).

It is a cyclic number.

It is not a de Polignac number, because 129268509 - 2¹ = 129268507 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129268501) 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, 21544749 + ... + 21544754.

It is an arithmetic number, because the mean of its divisors is an integer number (43089504).

Almost surely, 2^129268509 is an apocalyptic number.

It is an amenable number.

129268509 is a deficient number, since it is larger than the sum of its proper divisors (43089507).

129268509 is an equidigital number, since it uses as much as digits as its factorization.

129268509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43089506.

The product of its (nonzero) digits is 77760, while the sum is 42.

The square root of 129268509 is about 11369.6309966507. The cubic root of 129268509 is about 505.6277642184.

The spelling of 129268509 in words is "one hundred twenty-nine million, two hundred sixty-eight thousand, five hundred nine".