1221112222121 has 16 divisors (see below), whose sum is σ = 1424447762688. Its totient is φ = 1034457312000.

The previous prime is 1221112222111. The next prime is 1221112222129. The reversal of 1221112222121 is 1212222111221.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221112222121 is a prime.

It is a super-2 number, since 2×1221112222121² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221112222093 and 1221112222102.

It is not an unprimeable number, because it can be changed into a prime (1221112222129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32307905 + ... + 32345678.

It is an arithmetic number, because the mean of its divisors is an integer number (89027985168).

Almost surely, 2^{1221112222121} is an apocalyptic number.

1221112222121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221112222121 is a deficient number, since it is larger than the sum of its proper divisors (203335540567).

1221112222121 is a wasteful number, since it uses less digits than its factorization.

1221112222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64653712.

The product of its digits is 128, while the sum is 20.

Adding to 1221112222121 its reverse (1212222111221), we get a palindrome (2433334333342).

The spelling of 1221112222121 in words is "one trillion, two hundred twenty-one billion, one hundred twelve million, two hundred twenty-two thousand, one hundred twenty-one".