11111112121211 has 4 divisors (see below), whose sum is σ = 11594203952592. Its totient is φ = 10628020289832.

The previous prime is 11111112121133. The next prime is 11111112121217. The reversal of 11111112121211 is 11212121111111.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11111112121211 - 2²² = 11111107926907 is a prime.

It is a super-2 number, since 2×11111112121211² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11111112121211.

It is not an unprimeable number, because it can be changed into a prime (11111112121217) 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, 241545915656 + ... + 241545915701.

It is an arithmetic number, because the mean of its divisors is an integer number (2898550988148).

Almost surely, 2^{11111112121211} is an apocalyptic number.

11111112121211 is a deficient number, since it is larger than the sum of its proper divisors (483091831381).

11111112121211 is an equidigital number, since it uses as much as digits as its factorization.

11111112121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483091831380.

The product of its digits is 8, while the sum is 17.

Adding to 11111112121211 its reverse (11212121111111), we get a palindrome (22323233232322).

It can be divided in two parts, 11111 and 112121211, that multiplied together give a palindrome (1245778775421).

The spelling of 11111112121211 in words is "eleven trillion, one hundred eleven billion, one hundred twelve million, one hundred twenty-one thousand, two hundred eleven".