1221113121 has 16 divisors (see below), whose sum is σ = 1707375360. Its totient is φ = 775232640.

The previous prime is 1221113107. The next prime is 1221113137. The reversal of 1221113121 is 1213111221.

It is not a de Polignac number, because 1221113121 - 2⁷ = 1221112993 is a prime.

It is a super-2 number, since 2×1221113121² = 2982234508556721282, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221113121.

It is not an unprimeable number, because it can be changed into a prime (1221113221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89785 + ... + 102486.

It is an arithmetic number, because the mean of its divisors is an integer number (106710960).

Almost surely, 2^1221113121 is an apocalyptic number.

It is an amenable number.

1221113121 is a deficient number, since it is larger than the sum of its proper divisors (486262239).

1221113121 is a wasteful number, since it uses less digits than its factorization.

1221113121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192376.

The product of its digits is 24, while the sum is 15.

The square root of 1221113121 is about 34944.4290409788. The cubic root of 1221113121 is about 1068.8546048293.

Adding to 1221113121 its reverse (1213111221), we get a palindrome (2434224342).

The spelling of 1221113121 in words is "one billion, two hundred twenty-one million, one hundred thirteen thousand, one hundred twenty-one".