21321012313 has 2 divisors, whose sum is σ = 21321012314. Its totient is φ = 21321012312.

The previous prime is 21321012301. The next prime is 21321012319. The reversal of 21321012313 is 31321012312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19452438784 + 1868573529 = 139472^2 + 43227^2 .

It is a cyclic number.

It is not a de Polignac number, because 21321012313 - 2³³ = 12731077721 is a prime.

It is not a weakly prime, because it can be changed into another prime (21321012319) 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, 10660506156 + 10660506157.

It is an arithmetic number, because the mean of its divisors is an integer number (10660506157).

Almost surely, 2^21321012313 is an apocalyptic number.

It is an amenable number.

21321012313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321012313 is an equidigital number, since it uses as much as digits as its factorization.

21321012313 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 21321012313 its reverse (31321012312), we get a palindrome (52642024625).

Subtracting 21321012313 from its reverse (31321012312), we obtain a palindrome (9999999999).

The spelling of 21321012313 in words is "twenty-one billion, three hundred twenty-one million, twelve thousand, three hundred thirteen".