128887398920 has 96 divisors (see below), whose sum is σ = 337447788480. Its totient is φ = 44176245120.

The previous prime is 128887398853. The next prime is 128887398949. The reversal of 128887398920 is 29893788821.

It is a super-2 number, since 2×128887398920² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7845515 + ... + 7861925.

It is an arithmetic number, because the mean of its divisors is an integer number (3515081130).

Almost surely, 2^128887398920 is an apocalyptic number.

128887398920 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 128887398920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168723894240).

128887398920 is an abundant number, since it is smaller than the sum of its proper divisors (208560389560).

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

128887398920 is a wasteful number, since it uses less digits than its factorization.

128887398920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20443 (or 20432 counting only the distinct ones).

The product of its (nonzero) digits is 27869184, while the sum is 65.

The spelling of 128887398920 in words is "one hundred twenty-eight billion, eight hundred eighty-seven million, three hundred ninety-eight thousand, nine hundred twenty".