21001320323 has 2 divisors, whose sum is σ = 21001320324. Its totient is φ = 21001320322.

The previous prime is 21001320289. The next prime is 21001320343. The reversal of 21001320323 is 32302310012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21001320323 - 2¹⁰ = 21001319299 is a prime.

It is not a weakly prime, because it can be changed into another prime (21001320343) 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, 10500660161 + 10500660162.

It is an arithmetic number, because the mean of its divisors is an integer number (10500660162).

Almost surely, 2^21001320323 is an apocalyptic number.

21001320323 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001320323 is an equidigital number, since it uses as much as digits as its factorization.

21001320323 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21001320323 its reverse (32302310012), we get a palindrome (53303630335).

The spelling of 21001320323 in words is "twenty-one billion, one million, three hundred twenty thousand, three hundred twenty-three".