20421214243 has 2 divisors, whose sum is σ = 20421214244. Its totient is φ = 20421214242.

The previous prime is 20421214241. The next prime is 20421214271. The reversal of 20421214243 is 34241212402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20421214243 - 2¹ = 20421214241 is a prime.

Together with 20421214241, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20421214241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210607121 + 10210607122.

It is an arithmetic number, because the mean of its divisors is an integer number (10210607122).

Almost surely, 2^20421214243 is an apocalyptic number.

20421214243 is a deficient number, since it is larger than the sum of its proper divisors (1).

20421214243 is an equidigital number, since it uses as much as digits as its factorization.

20421214243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 20421214243 its reverse (34241212402), we get a palindrome (54662426645).

The spelling of 20421214243 in words is "twenty billion, four hundred twenty-one million, two hundred fourteen thousand, two hundred forty-three".