11943991 has 2 divisors, whose sum is σ = 11943992. Its totient is φ = 11943990.

The previous prime is 11943977. The next prime is 11944001. The reversal of 11943991 is 19934911.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11943991 - 2¹⁷ = 11812919 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11943991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11943941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5971995 + 5971996.

It is an arithmetic number, because the mean of its divisors is an integer number (5971996).

Almost surely, 2^11943991 is an apocalyptic number.

11943991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11943991 is an equidigital number, since it uses as much as digits as its factorization.

11943991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 37.

The square root of 11943991 is about 3456.0079571668. The cubic root of 11943991 is about 228.5861023504.

The spelling of 11943991 in words is "eleven million, nine hundred forty-three thousand, nine hundred ninety-one".