2091805128 has 128 divisors (see below), whose sum is σ = 6654700800. Its totient is φ = 596395008.

The previous prime is 2091805091. The next prime is 2091805129. The reversal of 2091805128 is 8215081902.

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 = 2091805092 and 2091805101.

It is not an unprimeable number, because it can be changed into a prime (2091805129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 895450 + ... + 897782.

It is an arithmetic number, because the mean of its divisors is an integer number (51989850).

Almost surely, 2^2091805128 is an apocalyptic number.

2091805128 is a gapful number since it is divisible by the number (28) 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 2091805128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3327350400).

2091805128 is an abundant number, since it is smaller than the sum of its proper divisors (4562895672).

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

2091805128 is a wasteful number, since it uses less digits than its factorization.

2091805128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2948 (or 2938 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 2091805128 is about 45736.2561651039. The cubic root of 2091805128 is about 1278.9112502944.

The spelling of 2091805128 in words is "two billion, ninety-one million, eight hundred five thousand, one hundred twenty-eight".