21131302321 has 2 divisors, whose sum is σ = 21131302322. Its totient is φ = 21131302320.

The previous prime is 21131302267. The next prime is 21131302327. The reversal of 21131302321 is 12320313112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14528927296 + 6602375025 = 120536^2 + 81255^2 .

It is a cyclic number.

It is not a de Polignac number, because 21131302321 - 2⁷ = 21131302193 is a prime.

It is not a weakly prime, because it can be changed into another prime (21131302327) 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, 10565651160 + 10565651161.

It is an arithmetic number, because the mean of its divisors is an integer number (10565651161).

Almost surely, 2^21131302321 is an apocalyptic number.

It is an amenable number.

21131302321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131302321 is an equidigital number, since it uses as much as digits as its factorization.

21131302321 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 19.

Adding to 21131302321 its reverse (12320313112), we get a palindrome (33451615433).

The spelling of 21131302321 in words is "twenty-one billion, one hundred thirty-one million, three hundred two thousand, three hundred twenty-one".