20002021021 has 2 divisors, whose sum is σ = 20002021022. Its totient is φ = 20002021020.

The previous prime is 20002020991. The next prime is 20002021049. The reversal of 20002021021 is 12012020002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14163380100 + 5838640921 = 119010^2 + 76411^2 .

It is a cyclic number.

It is not a de Polignac number, because 20002021021 - 2⁵ = 20002020989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20002020989 and 20002021007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20002021051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10001010510 + 10001010511.

It is an arithmetic number, because the mean of its divisors is an integer number (10001010511).

Almost surely, 2^20002021021 is an apocalyptic number.

It is an amenable number.

20002021021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20002021021 is an equidigital number, since it uses as much as digits as its factorization.

20002021021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 20002021021 its reverse (12012020002), we get a palindrome (32014041023).

The spelling of 20002021021 in words is "twenty billion, two million, twenty-one thousand, twenty-one".