21243422243 has 4 divisors (see below), whose sum is σ = 21244132848. Its totient is φ = 21242711640.

The previous prime is 21243422191. The next prime is 21243422261. The reversal of 21243422243 is 34222434212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21243422243 - 2³² = 16948454947 is a prime.

It is a super-3 number, since 3×21243422243³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21243422273) 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 in 3 ways as a sum of consecutive naturals, for example, 308396 + ... + 370937.

It is an arithmetic number, because the mean of its divisors is an integer number (5311033212).

Almost surely, 2^21243422243 is an apocalyptic number.

21243422243 is a deficient number, since it is larger than the sum of its proper divisors (710605).

21243422243 is an equidigital number, since it uses as much as digits as its factorization.

21243422243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710604.

The product of its digits is 18432, while the sum is 29.

Adding to 21243422243 its reverse (34222434212), we get a palindrome (55465856455).

The spelling of 21243422243 in words is "twenty-one billion, two hundred forty-three million, four hundred twenty-two thousand, two hundred forty-three".