2001220011221 has 4 divisors (see below), whose sum is σ = 2003195550252. Its totient is φ = 1999244472192.

The previous prime is 2001220011199. The next prime is 2001220011233. The reversal of 2001220011221 is 1221100221002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 920630655025 + 1080589356196 = 959495^2 + 1039514^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001220011221 - 2¹⁸ = 2001219749077 is a prime.

It is a super-2 number, since 2×2001220011221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001220011196 and 2001220011205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001220811221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 987767996 + ... + 987770021.

It is an arithmetic number, because the mean of its divisors is an integer number (500798887563).

Almost surely, 2^{2001220011221} is an apocalyptic number.

It is an amenable number.

2001220011221 is a deficient number, since it is larger than the sum of its proper divisors (1975539031).

2001220011221 is a wasteful number, since it uses less digits than its factorization.

2001220011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1975539030.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 2001220011221 its reverse (1221100221002), we get a palindrome (3222320232223).

The spelling of 2001220011221 in words is "two trillion, one billion, two hundred twenty million, eleven thousand, two hundred twenty-one".