11821143 has 4 divisors (see below), whose sum is σ = 15761528. Its totient is φ = 7880760.

The previous prime is 11821127. The next prime is 11821151. The reversal of 11821143 is 34112811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34112811 = 3 ⋅11370937.

It is not a de Polignac number, because 11821143 - 2⁴ = 11821127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11821123) 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 in 3 ways as a sum of consecutive naturals, for example, 1970188 + ... + 1970193.

It is an arithmetic number, because the mean of its divisors is an integer number (3940382).

Almost surely, 2^11821143 is an apocalyptic number.

11821143 is a deficient number, since it is larger than the sum of its proper divisors (3940385).

11821143 is an equidigital number, since it uses as much as digits as its factorization.

11821143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3940384.

The product of its digits is 192, while the sum is 21.

The square root of 11821143 is about 3438.1889127853. The cubic root of 11821143 is about 227.7997048272.

Adding to 11821143 its reverse (34112811), we get a palindrome (45933954).

The spelling of 11821143 in words is "eleven million, eight hundred twenty-one thousand, one hundred forty-three".