20284491221 has 2 divisors, whose sum is σ = 20284491222. Its totient is φ = 20284491220.

The previous prime is 20284491187. The next prime is 20284491259. The reversal of 20284491221 is 12219448202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19429572100 + 854919121 = 139390^2 + 29239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20284491221 is a prime.

It is a super-2 number, since 2×20284491221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20284491421) 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, 10142245610 + 10142245611.

It is an arithmetic number, because the mean of its divisors is an integer number (10142245611).

Almost surely, 2^20284491221 is an apocalyptic number.

It is an amenable number.

20284491221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20284491221 is an equidigital number, since it uses as much as digits as its factorization.

20284491221 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 35.

The spelling of 20284491221 in words is "twenty billion, two hundred eighty-four million, four hundred ninety-one thousand, two hundred twenty-one".