11111221212 has 96 divisors (see below), whose sum is σ = 32771676672. Its totient is φ = 2851220736.

The previous prime is 11111221201. The next prime is 11111221213. The reversal of 11111221212 is 21212211111.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 11111221191 and 11111221200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111221213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 97098 + ... + 177905.

It is an arithmetic number, because the mean of its divisors is an integer number (341371632).

Almost surely, 2^11111221212 is an apocalyptic number.

11111221212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

11111221212 is an abundant number, since it is smaller than the sum of its proper divisors (21660455460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11111221212 is a wasteful number, since it uses less digits than its factorization.

11111221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275067 (or 275065 counting only the distinct ones).

The product of its digits is 16, while the sum is 15.

Adding to 11111221212 its reverse (21212211111), we get a palindrome (32323432323).

The spelling of 11111221212 in words is "eleven billion, one hundred eleven million, two hundred twenty-one thousand, two hundred twelve".