128909724 has 24 divisors (see below), whose sum is σ = 301004928. Its totient is φ = 42939120.

The previous prime is 128909723. The next prime is 128909731. The reversal of 128909724 is 427909821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128909723) 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, 19039 + ... + 24905.

It is an arithmetic number, because the mean of its divisors is an integer number (12541872).

Almost surely, 2^128909724 is an apocalyptic number.

It is an amenable number.

128909724 is an abundant number, since it is smaller than the sum of its proper divisors (172095204).

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

128909724 is a wasteful number, since it uses less digits than its factorization.

128909724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7705 (or 7703 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 128909724 is about 11353.8418167596. The cubic root of 128909724 is about 505.1595404822.

The spelling of 128909724 in words is "one hundred twenty-eight million, nine hundred nine thousand, seven hundred twenty-four".