2128731840 has 280 divisors, whose sum is σ = 8019361152. Its totient is φ = 534159360.

The previous prime is 2128731827. The next prime is 2128731851. The reversal of 2128731840 is 481378212.

2128731840 is a `hidden beast` number, since 21 + 287 + 318 + 40 = 666.

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 = 2128731795 and 2128731804.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 438225 + ... + 443055.

Almost surely, 2^2128731840 is an apocalyptic number.

2128731840 is a gapful number since it is divisible by the number (20) 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 2128731840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4009680576).

2128731840 is an abundant number, since it is smaller than the sum of its proper divisors (5890629312).

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

2128731840 is a wasteful number, since it uses less digits than its factorization.

2128731840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4877 (or 4858 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 2128731840 is about 46138.1820188009. The cubic root of 2128731840 is about 1286.3929521779.

The spelling of 2128731840 in words is "two billion, one hundred twenty-eight million, seven hundred thirty-one thousand, eight hundred forty".