128521335306 has 288 divisors, whose sum is σ = 336798798336. Its totient is φ = 32550336000.

The previous prime is 128521335281. The next prime is 128521335317. The reversal of 128521335306 is 603533125821.

It is a super-2 number, since 2×128521335306² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 278787916 + ... + 278788376.

It is an arithmetic number, because the mean of its divisors is an integer number (1169440272).

Almost surely, 2^128521335306 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128521335306, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168399399168).

128521335306 is an abundant number, since it is smaller than the sum of its proper divisors (208277463030).

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

128521335306 is a wasteful number, since it uses less digits than its factorization.

128521335306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 39.

The spelling of 128521335306 in words is "one hundred twenty-eight billion, five hundred twenty-one million, three hundred thirty-five thousand, three hundred six".