129136128 has 80 divisors (see below), whose sum is σ = 375350976. Its totient is φ = 39127040.

The previous prime is 129136127. The next prime is 129136129. The reversal of 129136128 is 821631921.

It is an interprime number because it is at equal distance from previous prime (129136127) and next prime (129136129).

It is a super-2 number, since 2×129136128² = 33352279109664768, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129136121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13075 + ... + 20717.

Almost surely, 2^129136128 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 129136128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (187675488).

129136128 is an abundant number, since it is smaller than the sum of its proper divisors (246214848).

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

129136128 is an equidigital number, since it uses as much as digits as its factorization.

129136128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7675 (or 7659 counting only the distinct ones).

The product of its digits is 5184, while the sum is 33.

The square root of 129136128 is about 11363.8078125248. The cubic root of 129136128 is about 505.4551045567.

The spelling of 129136128 in words is "one hundred twenty-nine million, one hundred thirty-six thousand, one hundred twenty-eight".