129121867 has 4 divisors (see below), whose sum is σ = 147567856. Its totient is φ = 110675880.

The previous prime is 129121859. The next prime is 129121907. The reversal of 129121867 is 768121921.

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

It is not a de Polignac number, because 129121867 - 2³ = 129121859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129121847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9222984 + ... + 9222997.

It is an arithmetic number, because the mean of its divisors is an integer number (36891964).

Almost surely, 2^129121867 is an apocalyptic number.

129121867 is a deficient number, since it is larger than the sum of its proper divisors (18445989).

129121867 is an equidigital number, since it uses as much as digits as its factorization.

129121867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18445988.

The product of its digits is 12096, while the sum is 37.

The square root of 129121867 is about 11363.1803206673. The cubic root of 129121867 is about 505.4364974204.

The spelling of 129121867 in words is "one hundred twenty-nine million, one hundred twenty-one thousand, eight hundred sixty-seven".