11821979 has 4 divisors (see below), whose sum is σ = 12731376. Its totient is φ = 10912584.

The previous prime is 11821969. The next prime is 11821991. The reversal of 11821979 is 97912811.

11821979 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 11821979 - 2⁸ = 11821723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11821969) 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, 454679 + ... + 454704.

It is an arithmetic number, because the mean of its divisors is an integer number (3182844).

Almost surely, 2^11821979 is an apocalyptic number.

11821979 is a deficient number, since it is larger than the sum of its proper divisors (909397).

11821979 is an equidigital number, since it uses as much as digits as its factorization.

11821979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909396.

The product of its digits is 9072, while the sum is 38.

The square root of 11821979 is about 3438.3104862708. The cubic root of 11821979 is about 227.8050747553.

The spelling of 11821979 in words is "eleven million, eight hundred twenty-one thousand, nine hundred seventy-nine".