129785128 has 32 divisors (see below), whose sum is σ = 270488160. Its totient is φ = 57878080.

The previous prime is 129785099. The next prime is 129785129. The reversal of 129785128 is 821587921.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (129785129) 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, 9250 + ... + 18577.

It is an arithmetic number, because the mean of its divisors is an integer number (8452755).

Almost surely, 2^129785128 is an apocalyptic number.

It is an amenable number.

129785128 is an abundant number, since it is smaller than the sum of its proper divisors (140703032).

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

129785128 is a wasteful number, since it uses less digits than its factorization.

129785128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27897 (or 27893 counting only the distinct ones).

The product of its digits is 80640, while the sum is 43.

The square root of 129785128 is about 11392.3275936044. The cubic root of 129785128 is about 506.3004459612.

The spelling of 129785128 in words is "one hundred twenty-nine million, seven hundred eighty-five thousand, one hundred twenty-eight".