20021221101121 has 16 divisors (see below), whose sum is σ = 20623431643920. Its totient is φ = 19424508641280.

The previous prime is 20021221101071. The next prime is 20021221101169. The reversal of 20021221101121 is 12110112212002.

It can be written as a sum of positive squares in 8 ways, for example, as 356528410000 + 19664692691121 = 597100^2 + 4434489^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021221101121 - 2²¹ = 20021219003969 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021221101095 and 20021221101104.

It is not an unprimeable number, because it can be changed into a prime (20021221701121) 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, 21001665 + ... + 21934273.

It is an arithmetic number, because the mean of its divisors is an integer number (1288964477745).

Almost surely, 2^{20021221101121} is an apocalyptic number.

It is an amenable number.

20021221101121 is a deficient number, since it is larger than the sum of its proper divisors (602210542799).

20021221101121 is a wasteful number, since it uses less digits than its factorization.

20021221101121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 935556.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 20021221101121 its reverse (12110112212002), we get a palindrome (32131333313123).

The spelling of 20021221101121 in words is "twenty trillion, twenty-one billion, two hundred twenty-one million, one hundred one thousand, one hundred twenty-one".