21312231232213 has 2 divisors, whose sum is σ = 21312231232214. Its totient is φ = 21312231232212.

The previous prime is 21312231232211. The next prime is 21312231232241. The reversal of 21312231232213 is 31223213221312.

It is an a-pointer prime, because the next prime (21312231232241) can be obtained adding 21312231232213 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20063295348849 + 1248935883364 = 4479207^2 + 1117558^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312231232213 - 2¹ = 21312231232211 is a prime.

It is a super-2 number, since 2×21312231232213² (a number of 27 digits) contains 22 as substring.

Together with 21312231232211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312231232211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656115616106 + 10656115616107.

It is an arithmetic number, because the mean of its divisors is an integer number (10656115616107).

Almost surely, 2^{21312231232213} is an apocalyptic number.

It is an amenable number.

21312231232213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312231232213 is an equidigital number, since it uses as much as digits as its factorization.

21312231232213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 28.

Adding to 21312231232213 its reverse (31223213221312), we get a palindrome (52535444453525).

The spelling of 21312231232213 in words is "twenty-one trillion, three hundred twelve billion, two hundred thirty-one million, two hundred thirty-two thousand, two hundred thirteen".