129388428 has 180 divisors, whose sum is σ = 390602520. Its totient is φ = 37200384.

The previous prime is 129388403. The next prime is 129388429. The reversal of 129388428 is 824883921.

It is a super-2 number, since 2×129388428² = 33482730600622368, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (129388429) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 930783 + ... + 930921.

It is an arithmetic number, because the mean of its divisors is an integer number (2170014).

Almost surely, 2^129388428 is an apocalyptic number.

129388428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129388428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (195301260).

129388428 is an abundant number, since it is smaller than the sum of its proper divisors (261214092).

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

129388428 is a wasteful number, since it uses less digits than its factorization.

129388428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 174 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 129388428 is about 11374.9034281615. The cubic root of 129388428 is about 505.7840684267.

The spelling of 129388428 in words is "one hundred twenty-nine million, three hundred eighty-eight thousand, four hundred twenty-eight".