20984422021 has 2 divisors, whose sum is σ = 20984422022. Its totient is φ = 20984422020.

The previous prime is 20984421989. The next prime is 20984422049. The reversal of 20984422021 is 12022448902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18093209121 + 2891212900 = 134511^2 + 53770^2 .

It is a cyclic number.

It is not a de Polignac number, because 20984422021 - 2⁵ = 20984421989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20984422721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10492211010 + 10492211011.

It is an arithmetic number, because the mean of its divisors is an integer number (10492211011).

Almost surely, 2^20984422021 is an apocalyptic number.

It is an amenable number.

20984422021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20984422021 is an equidigital number, since it uses as much as digits as its factorization.

20984422021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 34.

The spelling of 20984422021 in words is "twenty billion, nine hundred eighty-four million, four hundred twenty-two thousand, twenty-one".