128312500 has 42 divisors (see below), whose sum is σ = 280816718. Its totient is φ = 51300000.

The previous prime is 128312477. The next prime is 128312507. The reversal of 128312500 is 5213821.

It can be written as a sum of positive squares in 7 ways, for example, as 128232976 + 79524 = 11324^2 + 282^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128312507) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 61474 + ... + 63526.

Almost surely, 2^128312500 is an apocalyptic number.

128312500 is a gapful number since it is divisible by the number (10) 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 128312500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140408359).

128312500 is an abundant number, since it is smaller than the sum of its proper divisors (152504218).

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

128312500 is an frugal number, since it uses more digits than its factorization.

128312500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2087 (or 2060 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 128312500 is about 11327.5107592092. The cubic root of 128312500 is about 504.3782171949.

The spelling of 128312500 in words is "one hundred twenty-eight million, three hundred twelve thousand, five hundred".