128081840 has 20 divisors (see below), whose sum is σ = 297790464. Its totient is φ = 51232704.

The previous prime is 128081809. The next prime is 128081843. The reversal of 128081840 is 48180821.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 128081797 and 128081806.

It is not an unprimeable number, because it can be changed into a prime (128081843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 800432 + ... + 800591.

Almost surely, 2^128081840 is an apocalyptic number.

128081840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128081840 is an abundant number, since it is smaller than the sum of its proper divisors (169708624).

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

128081840 is a wasteful number, since it uses less digits than its factorization.

128081840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1601036 (or 1601030 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 32.

The square root of 128081840 is about 11317.3247722242. The cubic root of 128081840 is about 504.0758053442.

The spelling of 128081840 in words is "one hundred twenty-eight million, eighty-one thousand, eight hundred forty".