20423412221 has 2 divisors, whose sum is σ = 20423412222. Its totient is φ = 20423412220.

The previous prime is 20423412187. The next prime is 20423412263. The reversal of 20423412221 is 12221432402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14687016100 + 5736396121 = 121190^2 + 75739^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20423412221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20423412271) 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, 10211706110 + 10211706111.

It is an arithmetic number, because the mean of its divisors is an integer number (10211706111).

Almost surely, 2^20423412221 is an apocalyptic number.

It is an amenable number.

20423412221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20423412221 is an equidigital number, since it uses as much as digits as its factorization.

20423412221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 20423412221 its reverse (12221432402), we get a palindrome (32644844623).

The spelling of 20423412221 in words is "twenty billion, four hundred twenty-three million, four hundred twelve thousand, two hundred twenty-one".