128506500 has 240 divisors, whose sum is σ = 443963520. Its totient is φ = 32270400.

The previous prime is 128506459. The next prime is 128506537. The reversal of 128506500 is 5605821.

128506500 is a `hidden beast` number, since 1 + 2 + 8 + 5 + 0 + 650 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 769417 + ... + 769583.

It is an arithmetic number, because the mean of its divisors is an integer number (1849848).

Almost surely, 2^128506500 is an apocalyptic number.

128506500 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 128506500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221981760).

128506500 is an abundant number, since it is smaller than the sum of its proper divisors (315457020).

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

128506500 is a wasteful number, since it uses less digits than its factorization.

128506500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 196 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 128506500 is about 11336.0707478385. The cubic root of 128506500 is about 504.6322846775.

The spelling of 128506500 in words is "one hundred twenty-eight million, five hundred six thousand, five hundred".