11111112221 has 8 divisors (see below), whose sum is σ = 12379112064. Its totient is φ = 9886095520.

The previous prime is 11111112209. The next prime is 11111112307. The reversal of 11111112221 is 12221111111.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11111112221 - 2⁶ = 11111112157 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11111112196 and 11111112205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111112421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10745240 + ... + 10746273.

It is an arithmetic number, because the mean of its divisors is an integer number (1547389008).

Almost surely, 2^11111112221 is an apocalyptic number.

11111112221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11111112221 is a deficient number, since it is larger than the sum of its proper divisors (1267999843).

11111112221 is a wasteful number, since it uses less digits than its factorization.

11111112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21491571.

The product of its digits is 8, while the sum is 14.

Adding to 11111112221 its reverse (12221111111), we get a palindrome (23332223332).

It can be divided in two parts, 111111 and 12221, that multiplied together give a palindrome (1357887531).

The spelling of 11111112221 in words is "eleven billion, one hundred eleven million, one hundred twelve thousand, two hundred twenty-one".