128897798820 has 384 divisors, whose sum is σ = 449432395776. Its totient is φ = 26933796864.

The previous prime is 128897798801. The next prime is 128897798831. The reversal of 128897798820 is 28897798821.

It is a super-2 number, since 2×128897798820² (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 127 ways as a sum of consecutive naturals, for example, 38975607 + ... + 38978913.

It is an arithmetic number, because the mean of its divisors is an integer number (1170396864).

Almost surely, 2^128897798820 is an apocalyptic number.

128897798820 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 128897798820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224716197888).

128897798820 is an abundant number, since it is smaller than the sum of its proper divisors (320534596956).

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

128897798820 is a wasteful number, since it uses less digits than its factorization.

128897798820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3499 (or 3497 counting only the distinct ones).

The product of its (nonzero) digits is 65028096, while the sum is 69.

Subtracting from 128897798820 its reverse (28897798821), we obtain a palindrome (99999999999).

The spelling of 128897798820 in words is "one hundred twenty-eight billion, eight hundred ninety-seven million, seven hundred ninety-eight thousand, eight hundred twenty".