2011221121 has 24 divisors (see below), whose sum is σ = 2541939624. Its totient is φ = 1577157120.

The previous prime is 2011221119. The next prime is 2011221127. The reversal of 2011221121 is 1211221102.

It can be written as a sum of positive squares in 4 ways, for example, as 36663025 + 1974558096 = 6055^2 + 44436^2 .

It is not a de Polignac number, because 2011221121 - 2¹ = 2011221119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is not an unprimeable number, because it can be changed into a prime (2011221127) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 58011 + ... + 85951.

It is an arithmetic number, because the mean of its divisors is an integer number (105914151).

Almost surely, 2^2011221121 is an apocalyptic number.

It is an amenable number.

2011221121 is a deficient number, since it is larger than the sum of its proper divisors (530718503).

2011221121 is a wasteful number, since it uses less digits than its factorization.

2011221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28081 (or 28074 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 2011221121 is about 44846.6400190694. The cubic root of 2011221121 is about 1262.2729446395.

Adding to 2011221121 its reverse (1211221102), we get a palindrome (3222442223).

The spelling of 2011221121 in words is "two billion, eleven million, two hundred twenty-one thousand, one hundred twenty-one".