128408520 has 64 divisors (see below), whose sum is σ = 398520000. Its totient is φ = 33060608.

The previous prime is 128408513. The next prime is 128408551. The reversal of 128408520 is 25804821.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14970 + ... + 21929.

It is an arithmetic number, because the mean of its divisors is an integer number (6226875).

Almost surely, 2^128408520 is an apocalyptic number.

128408520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128408520 is an abundant number, since it is smaller than the sum of its proper divisors (270111480).

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

128408520 is a wasteful number, since it uses less digits than its factorization.

128408520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36942 (or 36938 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 128408520 is about 11331.7483205373. The cubic root of 128408520 is about 504.5039994863.

The spelling of 128408520 in words is "one hundred twenty-eight million, four hundred eight thousand, five hundred twenty".