11111110221121 has 4 divisors (see below), whose sum is σ = 11112748793044. Its totient is φ = 11109471649200.

The previous prime is 11111110221091. The next prime is 11111110221131. The reversal of 11111110221121 is 12112201111111.

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 7861653330496 + 3249456890625 = 2803864^2 + 1802625^2 .

It is a cyclic number.

It is not a de Polignac number, because 11111110221121 - 2⁷ = 11111110220993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11111110221095 and 11111110221104.

It is not an unprimeable number, because it can be changed into a prime (11111110221131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 819275790 + ... + 819289351.

It is an arithmetic number, because the mean of its divisors is an integer number (2778187198261).

Almost surely, 2^{11111110221121} is an apocalyptic number.

It is an amenable number.

11111110221121 is a deficient number, since it is larger than the sum of its proper divisors (1638571923).

11111110221121 is an equidigital number, since it uses as much as digits as its factorization.

11111110221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1638571922.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 11111110221121 its reverse (12112201111111), we get a palindrome (23223311332232).

The spelling of 11111110221121 in words is "eleven trillion, one hundred eleven billion, one hundred ten million, two hundred twenty-one thousand, one hundred twenty-one".