128539720520 has 16 divisors (see below), whose sum is σ = 289214371260. Its totient is φ = 51415888192.

The previous prime is 128539720499. The next prime is 128539720559. The reversal of 128539720520 is 25027935821.

It can be written as a sum of positive squares in 2 ways, for example, as 128048034244 + 491686276 = 357838^2 + 22174^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1606746467 + ... + 1606746546.

Almost surely, 2^128539720520 is an apocalyptic number.

128539720520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128539720520 is an abundant number, since it is smaller than the sum of its proper divisors (160674650740).

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

128539720520 is a wasteful number, since it uses less digits than its factorization.

128539720520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3213493024 (or 3213493020 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 44.

The spelling of 128539720520 in words is "one hundred twenty-eight billion, five hundred thirty-nine million, seven hundred twenty thousand, five hundred twenty".