20002121220001 has 4 divisors (see below), whose sum is σ = 20004343440004. Its totient is φ = 19999899000000.

The previous prime is 20002121219947. The next prime is 20002121220047. The reversal of 20002121220001 is 10002212120002.

It is a happy number.

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 12555853643776 + 7446267576225 = 3543424^2 + 2728785^2 .

It is a cyclic number.

It is not a de Polignac number, because 20002121220001 - 2²⁵ = 20002087665569 is a prime.

It is a super-2 number, since 2×20002121220001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20002121290001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111096500 + ... + 1111114501.

It is an arithmetic number, because the mean of its divisors is an integer number (5001085860001).

Almost surely, 2^{20002121220001} is an apocalyptic number.

It is an amenable number.

20002121220001 is a deficient number, since it is larger than the sum of its proper divisors (2222220003).

20002121220001 is an equidigital number, since it uses as much as digits as its factorization.

20002121220001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2222220002.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20002121220001 its reverse (10002212120002), we get a palindrome (30004333340003).

Subtracting from 20002121220001 its reverse (10002212120002), we obtain a palindrome (9999909099999).

The spelling of 20002121220001 in words is "twenty trillion, two billion, one hundred twenty-one million, two hundred twenty thousand, one".