1221011121 has 12 divisors (see below), whose sum is σ = 1789471376. Its totient is φ = 740006520.

The previous prime is 1221011107. The next prime is 1221011177. The reversal of 1221011121 is 1211101221.

It is not a de Polignac number, because 1221011121 - 2¹⁰ = 1221010097 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1221011097 and 1221011106.

It is not an unprimeable number, because it can be changed into a prime (1221011021) 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, 1681471 + ... + 1682196.

Almost surely, 2^1221011121 is an apocalyptic number.

1221011121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221011121 is a deficient number, since it is larger than the sum of its proper divisors (568460255).

1221011121 is a wasteful number, since it uses less digits than its factorization.

1221011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3363692 (or 3363681 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

The square root of 1221011121 is about 34942.9695503974. The cubic root of 1221011121 is about 1068.8248434027.

Adding to 1221011121 its reverse (1211101221), we get a palindrome (2432112342).

The spelling of 1221011121 in words is "one billion, two hundred twenty-one million, eleven thousand, one hundred twenty-one".