11111122222121 has 8 divisors (see below), whose sum is σ = 11617264632960. Its totient is φ = 10606900656352.

The previous prime is 11111122222117. The next prime is 11111122222129. The reversal of 11111122222121 is 12122222111111.

It is a happy number.

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 11111122222121 - 2² = 11111122222117 is a prime.

It is a super-2 number, since 2×11111122222121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11111122222093 and 11111122222102.

It is not an unprimeable number, because it can be changed into a prime (11111122222129) 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, 480199436 + ... + 480222573.

It is an arithmetic number, because the mean of its divisors is an integer number (1452158079120).

Almost surely, 2^{11111122222121} is an apocalyptic number.

It is an amenable number.

11111122222121 is a deficient number, since it is larger than the sum of its proper divisors (506142410839).

11111122222121 is an equidigital number, since it uses as much as digits as its factorization.

11111122222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 960422535.

The product of its digits is 64, while the sum is 20.

Adding to 11111122222121 its reverse (12122222111111), we get a palindrome (23233344333232).

The spelling of 11111122222121 in words is "eleven trillion, one hundred eleven billion, one hundred twenty-two million, two hundred twenty-two thousand, one hundred twenty-one".