213423321421 has 2 divisors, whose sum is σ = 213423321422. Its totient is φ = 213423321420.

The previous prime is 213423321373. The next prime is 213423321437. The reversal of 213423321421 is 124123324312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188343848196 + 25079473225 = 433986^2 + 158365^2 .

It is a cyclic number.

It is not a de Polignac number, because 213423321421 - 2⁹ = 213423320909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213423321421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213423325421) 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, 106711660710 + 106711660711.

It is an arithmetic number, because the mean of its divisors is an integer number (106711660711).

Almost surely, 2^213423321421 is an apocalyptic number.

It is an amenable number.

213423321421 is a deficient number, since it is larger than the sum of its proper divisors (1).

213423321421 is an equidigital number, since it uses as much as digits as its factorization.

213423321421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 28.

Adding to 213423321421 its reverse (124123324312), we get a palindrome (337546645733).

The spelling of 213423321421 in words is "two hundred thirteen billion, four hundred twenty-three million, three hundred twenty-one thousand, four hundred twenty-one".