1111222212121 has 12 divisors (see below), whose sum is σ = 1292725618740. Its totient is φ = 952417697280.

The previous prime is 1111222212073. The next prime is 1111222212151. The reversal of 1111222212121 is 1212122221111.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 380949418521 + 730272793600 = 617211^2 + 854560^2 .

It is not a de Polignac number, because 1111222212121 - 2¹⁷ = 1111222081049 is a prime.

It is a super-2 number, since 2×1111222212121² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1111222212151) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 119565 + ... + 1495573.

It is an arithmetic number, because the mean of its divisors is an integer number (107727134895).

Almost surely, 2^{1111222212121} is an apocalyptic number.

It is an amenable number.

1111222212121 is a deficient number, since it is larger than the sum of its proper divisors (181503406619).

1111222212121 is a wasteful number, since it uses less digits than its factorization.

1111222212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392504 (or 1392497 counting only the distinct ones).

The product of its digits is 64, while the sum is 19.

Adding to 1111222212121 its reverse (1212122221111), we get a palindrome (2323344433232).

The spelling of 1111222212121 in words is "one trillion, one hundred eleven billion, two hundred twenty-two million, two hundred twelve thousand, one hundred twenty-one".