11111121112221 has 48 divisors (see below), whose sum is σ = 17481594049920. Its totient is φ = 6759636105600.

The previous prime is 11111121112213. The next prime is 11111121112271. The reversal of 11111121112221 is 12221112111111.

11111121112221 is a `hidden beast` number, since 111 + 111 + 211 + 12 + 221 = 666.

It is not a de Polignac number, because 11111121112221 - 2³ = 11111121112213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11111121112194 and 11111121112203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111121112271) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7074000 + ... + 8500806.

It is an arithmetic number, because the mean of its divisors is an integer number (364199876040).

Almost surely, 2^{11111121112221} is an apocalyptic number.

It is an amenable number.

11111121112221 is a deficient number, since it is larger than the sum of its proper divisors (6370472937699).

11111121112221 is a wasteful number, since it uses less digits than its factorization.

11111121112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1427586 (or 1427583 counting only the distinct ones).

The product of its digits is 16, while the sum is 18.

Adding to 11111121112221 its reverse (12221112111111), we get a palindrome (23332233223332).

The spelling of 11111121112221 in words is "eleven trillion, one hundred eleven billion, one hundred twenty-one million, one hundred twelve thousand, two hundred twenty-one".