1221122112111 has 48 divisors (see below), whose sum is σ = 1995935829888. Its totient is φ = 739897092000.

The previous prime is 1221122112097. The next prime is 1221122112121. The reversal of 1221122112111 is 1112112211221.

It is a happy number.

It is not a de Polignac number, because 1221122112111 - 2⁷ = 1221122111983 is a prime.

It is a super-4 number, since 4×1221122112111⁴ (a number of 49 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221122112121) 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, 11593836 + ... + 11698686.

It is an arithmetic number, because the mean of its divisors is an integer number (41581996456).

Almost surely, 2^{1221122112111} is an apocalyptic number.

1221122112111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221122112111 is a deficient number, since it is larger than the sum of its proper divisors (774813717777).

1221122112111 is a wasteful number, since it uses less digits than its factorization.

1221122112111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109234 (or 109222 counting only the distinct ones).

The product of its digits is 32, while the sum is 18.

Adding to 1221122112111 its reverse (1112112211221), we get a palindrome (2333234323332).

The spelling of 1221122112111 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, one hundred twelve thousand, one hundred eleven".