2001220121121 has 16 divisors (see below), whose sum is σ = 2874412813440. Its totient is φ = 1231148943360.

The previous prime is 2001220121113. The next prime is 2001220121129. The reversal of 2001220121121 is 1211210221002.

It is an interprime number because it is at equal distance from previous prime (2001220121113) and next prime (2001220121129).

It is not a de Polignac number, because 2001220121121 - 2³ = 2001220121113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2001220121121.

It is not an unprimeable number, because it can be changed into a prime (2001220121129) 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, 7600800 + ... + 7859681.

It is an arithmetic number, because the mean of its divisors is an integer number (179650800840).

Almost surely, 2^{2001220121121} is an apocalyptic number.

It is an amenable number.

2001220121121 is a deficient number, since it is larger than the sum of its proper divisors (873192692319).

2001220121121 is a wasteful number, since it uses less digits than its factorization.

2001220121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15463816.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 2001220121121 its reverse (1211210221002), we get a palindrome (3212430342123).

The spelling of 2001220121121 in words is "two trillion, one billion, two hundred twenty million, one hundred twenty-one thousand, one hundred twenty-one".