21344042231 has 2 divisors, whose sum is σ = 21344042232. Its totient is φ = 21344042230.

The previous prime is 21344042227. The next prime is 21344042243. The reversal of 21344042231 is 13224044312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21344042231 - 2² = 21344042227 is a prime.

It is a super-2 number, since 2×21344042231² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21344042231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21344042261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672021115 + 10672021116.

It is an arithmetic number, because the mean of its divisors is an integer number (10672021116).

Almost surely, 2^21344042231 is an apocalyptic number.

21344042231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21344042231 is an equidigital number, since it uses as much as digits as its factorization.

21344042231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21344042231 its reverse (13224044312), we get a palindrome (34568086543).

The spelling of 21344042231 in words is "twenty-one billion, three hundred forty-four million, forty-two thousand, two hundred thirty-one".