21023023321 has 2 divisors, whose sum is σ = 21023023322. Its totient is φ = 21023023320.

The previous prime is 21023023319. The next prime is 21023023349. The reversal of 21023023321 is 12332032012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20725633296 + 297390025 = 143964^2 + 17245^2 .

It is a cyclic number.

It is not a de Polignac number, because 21023023321 - 2¹ = 21023023319 is a prime.

Together with 21023023319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21023023381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511511660 + 10511511661.

It is an arithmetic number, because the mean of its divisors is an integer number (10511511661).

Almost surely, 2^21023023321 is an apocalyptic number.

It is an amenable number.

21023023321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21023023321 is an equidigital number, since it uses as much as digits as its factorization.

21023023321 is an evil number, because the sum of its binary digits is even.

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

Adding to 21023023321 its reverse (12332032012), we get a palindrome (33355055333).

The spelling of 21023023321 in words is "twenty-one billion, twenty-three million, twenty-three thousand, three hundred twenty-one".