1221111022121 has 8 divisors (see below), whose sum is σ = 1249561921344. Its totient is φ = 1192662530640.

The previous prime is 1221111022099. The next prime is 1221111022189. The reversal of 1221111022121 is 1212201111221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221111022121 is a prime.

It is a super-2 number, since 2×1221111022121² (a number of 25 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 1221111022121.

It is not an unprimeable number, because it can be changed into a prime (1221111522121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 445175 + ... + 1624931.

It is an arithmetic number, because the mean of its divisors is an integer number (156195240168).

Almost surely, 2^{1221111022121} is an apocalyptic number.

It is an amenable number.

1221111022121 is a deficient number, since it is larger than the sum of its proper divisors (28450899223).

1221111022121 is a wasteful number, since it uses less digits than its factorization.

1221111022121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1203871.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1221111022121 its reverse (1212201111221), we get a palindrome (2433312133342).

The spelling of 1221111022121 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, twenty-two thousand, one hundred twenty-one".