128806920 has 144 divisors (see below), whose sum is σ = 460294380. Its totient is φ = 31215360.

The previous prime is 128806913. The next prime is 128806949. The reversal of 128806920 is 29608821.

It can be written as a sum of positive squares in 2 ways, for example, as 121484484 + 7322436 = 11022^2 + 2706^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 42082 + ... + 45038.

Almost surely, 2^128806920 is an apocalyptic number.

128806920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128806920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230147190).

128806920 is an abundant number, since it is smaller than the sum of its proper divisors (331487460).

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

128806920 is a wasteful number, since it uses less digits than its factorization.

128806920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2996 (or 2978 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 128806920 is about 11349.3136356345. The cubic root of 128806920 is about 505.0252184903.

The spelling of 128806920 in words is "one hundred twenty-eight million, eight hundred six thousand, nine hundred twenty".