2091986891 has 8 divisors (see below), whose sum is σ = 2171519280. Its totient is φ = 2012947552.

The previous prime is 2091986881. The next prime is 2091986893. The reversal of 2091986891 is 1986891902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2091986891 - 2²² = 2087792587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2091986893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114605 + ... + 131598.

It is an arithmetic number, because the mean of its divisors is an integer number (271439910).

Almost surely, 2^2091986891 is an apocalyptic number.

2091986891 is a deficient number, since it is larger than the sum of its proper divisors (79532389).

2091986891 is a wasteful number, since it uses less digits than its factorization.

2091986891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246525.

The product of its (nonzero) digits is 559872, while the sum is 53.

The square root of 2091986891 is about 45738.2431997557. The cubic root of 2091986891 is about 1278.9482919878.

The spelling of 2091986891 in words is "two billion, ninety-one million, nine hundred eighty-six thousand, eight hundred ninety-one".