128388820 has 36 divisors (see below), whose sum is σ = 313637940. Its totient is φ = 44018688.

The previous prime is 128388809. The next prime is 128388839. The reversal of 128388820 is 28883821.

It can be written as a sum of positive squares in 2 ways, for example, as 76807696 + 51581124 = 8764^2 + 7182^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64525 + ... + 66484.

It is an arithmetic number, because the mean of its divisors is an integer number (8712165).

Almost surely, 2^128388820 is an apocalyptic number.

128388820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128388820 is an abundant number, since it is smaller than the sum of its proper divisors (185249120).

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

128388820 is a wasteful number, since it uses less digits than its factorization.

128388820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131032 (or 131023 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 40.

The square root of 128388820 is about 11330.8790479821. The cubic root of 128388820 is about 504.4781984022.

The spelling of 128388820 in words is "one hundred twenty-eight million, three hundred eighty-eight thousand, eight hundred twenty".