20201030021 has 2 divisors, whose sum is σ = 20201030022. Its totient is φ = 20201030020.

The previous prime is 20201029993. The next prime is 20201030023. The reversal of 20201030021 is 12003010202.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19800429796 + 400600225 = 140714^2 + 20015^2 .

It is a cyclic number.

It is not a de Polignac number, because 20201030021 - 2¹⁰ = 20201028997 is a prime.

It is a super-2 number, since 2×20201030021² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 20201030023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20201029984 and 20201030011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20201030023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100515010 + 10100515011.

It is an arithmetic number, because the mean of its divisors is an integer number (10100515011).

Almost surely, 2^20201030021 is an apocalyptic number.

It is an amenable number.

20201030021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20201030021 is an equidigital number, since it uses as much as digits as its factorization.

20201030021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 20201030021 its reverse (12003010202), we get a palindrome (32204040223).

The spelling of 20201030021 in words is "twenty billion, two hundred one million, thirty thousand, twenty-one".