21301322381 has 2 divisors, whose sum is σ = 21301322382. Its totient is φ = 21301322380.

The previous prime is 21301322369. The next prime is 21301322431. The reversal of 21301322381 is 18322310312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11522090281 + 9779232100 = 107341^2 + 98890^2 .

It is a cyclic number.

It is not a de Polignac number, because 21301322381 - 2¹⁸ = 21301060237 is a prime.

It is a super-2 number, since 2×21301322381² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21301322381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21301322321) 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, 10650661190 + 10650661191.

It is an arithmetic number, because the mean of its divisors is an integer number (10650661191).

Almost surely, 2^21301322381 is an apocalyptic number.

It is an amenable number.

21301322381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21301322381 is an equidigital number, since it uses as much as digits as its factorization.

21301322381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 26.

Adding to 21301322381 its reverse (18322310312), we get a palindrome (39623632693).

The spelling of 21301322381 in words is "twenty-one billion, three hundred one million, three hundred twenty-two thousand, three hundred eighty-one".