21031220323 has 2 divisors, whose sum is σ = 21031220324. Its totient is φ = 21031220322.

The previous prime is 21031220293. The next prime is 21031220339. The reversal of 21031220323 is 32302213012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21031220323 - 2¹³ = 21031212131 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21031220323.

It is not a weakly prime, because it can be changed into another prime (21031220423) 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, 10515610161 + 10515610162.

It is an arithmetic number, because the mean of its divisors is an integer number (10515610162).

Almost surely, 2^21031220323 is an apocalyptic number.

21031220323 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031220323 is an equidigital number, since it uses as much as digits as its factorization.

21031220323 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 21031220323 its reverse (32302213012), we get a palindrome (53333433335).

The spelling of 21031220323 in words is "twenty-one billion, thirty-one million, two hundred twenty thousand, three hundred twenty-three".