11881891 has 4 divisors (see below), whose sum is σ = 13579312. Its totient is φ = 10184472.

The previous prime is 11881879. The next prime is 11881901. The reversal of 11881891 is 19818811.

11881891 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11881891 - 2⁹ = 11881379 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11881891.

It is not an unprimeable number, because it can be changed into a prime (11881801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 848700 + ... + 848713.

It is an arithmetic number, because the mean of its divisors is an integer number (3394828).

Almost surely, 2^11881891 is an apocalyptic number.

11881891 is a deficient number, since it is larger than the sum of its proper divisors (1697421).

11881891 is an equidigital number, since it uses as much as digits as its factorization.

11881891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1697420.

The product of its digits is 4608, while the sum is 37.

The square root of 11881891 is about 3447.0118943804. The cubic root of 11881891 is about 228.1892537089.

The spelling of 11881891 in words is "eleven million, eight hundred eighty-one thousand, eight hundred ninety-one".