11991839 has 2 divisors, whose sum is σ = 11991840. Its totient is φ = 11991838.

The previous prime is 11991781. The next prime is 11991911. The reversal of 11991839 is 93819911.

It is a happy number.

11991839 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11991839 - 2⁸ = 11991583 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 11991796 and 11991805.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11991139) 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 as a sum of consecutive naturals, namely, 5995919 + 5995920.

It is an arithmetic number, because the mean of its divisors is an integer number (5995920).

Almost surely, 2^11991839 is an apocalyptic number.

11991839 is a deficient number, since it is larger than the sum of its proper divisors (1).

11991839 is an equidigital number, since it uses as much as digits as its factorization.

11991839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17496, while the sum is 41.

The square root of 11991839 is about 3462.9234759088. The cubic root of 11991839 is about 228.8909366689.

The spelling of 11991839 in words is "eleven million, nine hundred ninety-one thousand, eight hundred thirty-nine".