129121608 has 128 divisors (see below), whose sum is σ = 406840320. Its totient is φ = 33173760.

The previous prime is 129121607. The next prime is 129121627. The reversal of 129121608 is 806121921.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (129121607) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 197410 + ... + 198062.

It is an arithmetic number, because the mean of its divisors is an integer number (3178440).

Almost surely, 2^129121608 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129121608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203420160).

129121608 is an abundant number, since it is smaller than the sum of its proper divisors (277718712).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129121608 is a wasteful number, since it uses less digits than its factorization.

129121608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787 (or 783 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 129121608 is about 11363.1689242042. The cubic root of 129121608 is about 505.4361594757.

The spelling of 129121608 in words is "one hundred twenty-nine million, one hundred twenty-one thousand, six hundred eight".