128840940 has 72 divisors (see below), whose sum is σ = 407822688. Its totient is φ = 32862720.

The previous prime is 128840923. The next prime is 128840969. The reversal of 128840940 is 49048821.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 128840895 and 128840904.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11421 + ... + 19700.

It is an arithmetic number, because the mean of its divisors is an integer number (5664204).

Almost surely, 2^128840940 is an apocalyptic number.

128840940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128840940 is an abundant number, since it is smaller than the sum of its proper divisors (278981748).

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

128840940 is a wasteful number, since it uses less digits than its factorization.

128840940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31159 (or 31154 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 128840940 is about 11350.8123057339. The cubic root of 128840940 is about 505.0696763646.

The spelling of 128840940 in words is "one hundred twenty-eight million, eight hundred forty thousand, nine hundred forty".