128521220480 has 64 divisors (see below), whose sum is σ = 307295138880. Its totient is φ = 51400273920.

The previous prime is 128521220453. The next prime is 128521220507. The reversal of 128521220480 is 84022125821.

It is an interprime number because it is at equal distance from previous prime (128521220453) and next prime (128521220507).

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×128521220480² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 128521220480.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5441657 + ... + 5465223.

It is an arithmetic number, because the mean of its divisors is an integer number (4801486545).

Almost surely, 2^128521220480 is an apocalyptic number.

128521220480 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128521220480 is an abundant number, since it is smaller than the sum of its proper divisors (178773918400).

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

128521220480 is an equidigital number, since it uses as much as digits as its factorization.

128521220480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32107 (or 32095 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 35.

The spelling of 128521220480 in words is "one hundred twenty-eight billion, five hundred twenty-one million, two hundred twenty thousand, four hundred eighty".