2001221121 has 8 divisors (see below), whose sum is σ = 2669405760. Its totient is φ = 1333591952.

The previous prime is 2001221119. The next prime is 2001221141. The reversal of 2001221121 is 1211221002.

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

It is a cyclic number.

It is not a de Polignac number, because 2001221121 - 2¹ = 2001221119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001221097 and 2001221106.

It is not an unprimeable number, because it can be changed into a prime (2001221141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130386 + ... + 144923.

It is an arithmetic number, because the mean of its divisors is an integer number (333675720).

Almost surely, 2^2001221121 is an apocalyptic number.

It is an amenable number.

2001221121 is a deficient number, since it is larger than the sum of its proper divisors (668184639).

2001221121 is a wasteful number, since it uses less digits than its factorization.

2001221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277735.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 2001221121 is about 44735.0100145289. The cubic root of 2001221121 is about 1260.1774170681.

Adding to 2001221121 its reverse (1211221002), we get a palindrome (3212442123).

The spelling of 2001221121 in words is "two billion, one million, two hundred twenty-one thousand, one hundred twenty-one".