21313301221 has 2 divisors, whose sum is σ = 21313301222. Its totient is φ = 21313301220.

The previous prime is 21313301213. The next prime is 21313301231. The reversal of 21313301221 is 12210331312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14770756225 + 6542544996 = 121535^2 + 80886^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313301221 - 2³ = 21313301213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21313301201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656650610 + 10656650611.

It is an arithmetic number, because the mean of its divisors is an integer number (10656650611).

Almost surely, 2^21313301221 is an apocalyptic number.

It is an amenable number.

21313301221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21313301221 is an equidigital number, since it uses as much as digits as its factorization.

21313301221 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 21313301221 its reverse (12210331312), we get a palindrome (33523632533).

The spelling of 21313301221 in words is "twenty-one billion, three hundred thirteen million, three hundred one thousand, two hundred twenty-one".