21231020323 has 2 divisors, whose sum is σ = 21231020324. Its totient is φ = 21231020322.

The previous prime is 21231020311. The next prime is 21231020329. The reversal of 21231020323 is 32302013212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231020323 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21231020323.

It is not a weakly prime, because it can be changed into another prime (21231020329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615510161 + 10615510162.

It is an arithmetic number, because the mean of its divisors is an integer number (10615510162).

Almost surely, 2^21231020323 is an apocalyptic number.

21231020323 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231020323 is an equidigital number, since it uses as much as digits as its factorization.

21231020323 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21231020323 its reverse (32302013212), we get a palindrome (53533033535).

The spelling of 21231020323 in words is "twenty-one billion, two hundred thirty-one million, twenty thousand, three hundred twenty-three".