11813891 has 2 divisors, whose sum is σ = 11813892. Its totient is φ = 11813890.

The previous prime is 11813887. The next prime is 11813899. The reversal of 11813891 is 19831811.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11813891 - 2² = 11813887 is a prime.

It is not a weakly prime, because it can be changed into another prime (11813899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5906945 + 5906946.

It is an arithmetic number, because the mean of its divisors is an integer number (5906946).

Almost surely, 2^11813891 is an apocalyptic number.

11813891 is a deficient number, since it is larger than the sum of its proper divisors (1).

11813891 is an equidigital number, since it uses as much as digits as its factorization.

11813891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 32.

The square root of 11813891 is about 3437.1341259834. The cubic root of 11813891 is about 227.7531120007.

The spelling of 11813891 in words is "eleven million, eight hundred thirteen thousand, eight hundred ninety-one".