128706533956 has 288 divisors, whose sum is σ = 317998227456. Its totient is φ = 44255203200.

The previous prime is 128706533951. The next prime is 128706533983. The reversal of 128706533956 is 659335607821.

It is a junction number, because it is equal to n+sod(n) for n = 128706533897 and 128706533906.

It is not an unprimeable number, because it can be changed into a prime (128706533951) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1550681091 + ... + 1550681173.

It is an arithmetic number, because the mean of its divisors is an integer number (1104160512).

Almost surely, 2^128706533956 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128706533956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158999113728).

128706533956 is an abundant number, since it is smaller than the sum of its proper divisors (189291693500).

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

128706533956 is a wasteful number, since it uses less digits than its factorization.

128706533956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 8164800, while the sum is 55.

The spelling of 128706533956 in words is "one hundred twenty-eight billion, seven hundred six million, five hundred thirty-three thousand, nine hundred fifty-six".