11212124221 has 4 divisors (see below), whose sum is σ = 11216450812. Its totient is φ = 11207797632.

The previous prime is 11212124201. The next prime is 11212124227. The reversal of 11212124221 is 12242121211.

11212124221 is digitally balanced in base 2, 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 can be written as a sum of positive squares in 2 ways, for example, as 6477996196 + 4734128025 = 80486^2 + 68805^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11212124221 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 (11212124227) 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 in 3 ways as a sum of consecutive naturals, for example, 2159406 + ... + 2164591.

It is an arithmetic number, because the mean of its divisors is an integer number (2804112703).

Almost surely, 2^11212124221 is an apocalyptic number.

It is an amenable number.

11212124221 is a deficient number, since it is larger than the sum of its proper divisors (4326591).

11212124221 is an equidigital number, since it uses as much as digits as its factorization.

11212124221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4326590.

The product of its digits is 128, while the sum is 19.

Adding to 11212124221 its reverse (12242121211), we get a palindrome (23454245432).

The spelling of 11212124221 in words is "eleven billion, two hundred twelve million, one hundred twenty-four thousand, two hundred twenty-one".