2001022221121 has 32 divisors (see below), whose sum is σ = 2502553190400. Its totient is φ = 1554382579200.

The previous prime is 2001022221101. The next prime is 2001022221157. The reversal of 2001022221121 is 1211222201002.

It is a happy number.

It is not a de Polignac number, because 2001022221121 - 2⁵ = 2001022221089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001022221095 and 2001022221104.

It is not an unprimeable number, because it can be changed into a prime (2001022221101) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 204368736 + ... + 204378526.

It is an arithmetic number, because the mean of its divisors is an integer number (78204787200).

Almost surely, 2^{2001022221121} is an apocalyptic number.

It is an amenable number.

2001022221121 is a deficient number, since it is larger than the sum of its proper divisors (501530969279).

2001022221121 is a wasteful number, since it uses less digits than its factorization.

2001022221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17805.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2001022221121 its reverse (1211222201002), we get a palindrome (3212244422123).

The spelling of 2001022221121 in words is "two trillion, one billion, twenty-two million, two hundred twenty-one thousand, one hundred twenty-one".