20021201221121 has 8 divisors (see below), whose sum is σ = 20383733721384. Its totient is φ = 19659775691520.

The previous prime is 20021201221081. The next prime is 20021201221127. The reversal of 20021201221121 is 12112210212002.

It can be written as a sum of positive squares in 4 ways, for example, as 7531636225 + 20013669584896 = 86785^2 + 4473664^2 .

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 20021201221121 - 2²⁶ = 20021134112257 is a prime.

It is a super-3 number, since 3×20021201221121³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20021201221121.

It is not an unprimeable number, because it can be changed into a prime (20021201221127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 276706166 + ... + 276778511.

It is an arithmetic number, because the mean of its divisors is an integer number (2547966715173).

Almost surely, 2^{20021201221121} is an apocalyptic number.

It is an amenable number.

20021201221121 is a deficient number, since it is larger than the sum of its proper divisors (362532500263).

20021201221121 is an equidigital number, since it uses as much as digits as its factorization.

20021201221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553485331.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20021201221121 its reverse (12112210212002), we get a palindrome (32133411433123).

The spelling of 20021201221121 in words is "twenty trillion, twenty-one billion, two hundred one million, two hundred twenty-one thousand, one hundred twenty-one".