20203220021 has 2 divisors, whose sum is σ = 20203220022. Its totient is φ = 20203220020.

The previous prime is 20203220017. The next prime is 20203220039. The reversal of 20203220021 is 12002230202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20200936900 + 2283121 = 142130^2 + 1511^2 .

It is a cyclic number.

It is not a de Polignac number, because 20203220021 - 2² = 20203220017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20203219978 and 20203220005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20203220041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10101610010 + 10101610011.

It is an arithmetic number, because the mean of its divisors is an integer number (10101610011).

Almost surely, 2^20203220021 is an apocalyptic number.

It is an amenable number.

20203220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20203220021 is an equidigital number, since it uses as much as digits as its factorization.

20203220021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 14.

Adding to 20203220021 its reverse (12002230202), we get a palindrome (32205450223).

The spelling of 20203220021 in words is "twenty billion, two hundred three million, two hundred twenty thousand, twenty-one".