128638730220 has 768 divisors, whose sum is σ = 498548736000. Its totient is φ = 23922708480.

The previous prime is 128638730201. The next prime is 128638730221. The reversal of 128638730220 is 22037836821.

It is a super-2 number, since 2×128638730220² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (128638730221) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 561741066 + ... + 561741294.

It is an arithmetic number, because the mean of its divisors is an integer number (649152000).

Almost surely, 2^128638730220 is an apocalyptic number.

128638730220 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 128638730220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249274368000).

128638730220 is an abundant number, since it is smaller than the sum of its proper divisors (369910005780).

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

128638730220 is a wasteful number, since it uses less digits than its factorization.

128638730220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518 (or 516 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 42.

It can be divided in two parts, 128638 and 730220, that added together give a palindrome (858858).

The spelling of 128638730220 in words is "one hundred twenty-eight billion, six hundred thirty-eight million, seven hundred thirty thousand, two hundred twenty".