128820736 has 80 divisors (see below), whose sum is σ = 285048720. Its totient is φ = 57671680.

The previous prime is 128820683. The next prime is 128820737. The reversal of 128820736 is 637028821.

It is a junction number, because it is equal to n+sod(n) for n = 128820695 and 128820704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128820737) 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, 501120 + ... + 501376.

It is an arithmetic number, because the mean of its divisors is an integer number (3563109).

Almost surely, 2^128820736 is an apocalyptic number.

128820736 is a gapful number since it is divisible by the number (16) 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 128820736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142524360).

128820736 is an abundant number, since it is smaller than the sum of its proper divisors (156227984).

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

128820736 is an equidigital number, since it uses as much as digits as its factorization.

128820736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 128820736 is about 11349.9222904829. The cubic root of 128820736 is about 505.0432744016.

The spelling of 128820736 in words is "one hundred twenty-eight million, eight hundred twenty thousand, seven hundred thirty-six".