2128985856 has 180 divisors, whose sum is σ = 6429929352. Its totient is φ = 700545024.

The previous prime is 2128985849. The next prime is 2128985863. The reversal of 2128985856 is 6585898212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2128985849) and next prime (2128985863).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1720470 + ... + 1721706.

Almost surely, 2^2128985856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2128985856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3214964676).

2128985856 is an abundant number, since it is smaller than the sum of its proper divisors (4300943496).

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

2128985856 is an equidigital number, since it uses as much as digits as its factorization.

2128985856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1348 (or 1325 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 54.

The square root of 2128985856 is about 46140.9347109484. The cubic root of 2128985856 is about 1286.4441174444. Note that the first 3 decimals are identical.

The spelling of 2128985856 in words is "two billion, one hundred twenty-eight million, nine hundred eighty-five thousand, eight hundred fifty-six".