21211326323381 has 2 divisors, whose sum is σ = 21211326323382. Its totient is φ = 21211326323380.

The previous prime is 21211326323359. The next prime is 21211326323419. The reversal of 21211326323381 is 18332362311212.

It is an a-pointer prime, because the next prime (21211326323419) can be obtained adding 21211326323381 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13069605966481 + 8141720356900 = 3615191^2 + 2853370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211326323381 is a prime.

It is a super-2 number, since 2×21211326323381² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211326323351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605663161690 + 10605663161691.

It is an arithmetic number, because the mean of its divisors is an integer number (10605663161691).

Almost surely, 2^{21211326323381} is an apocalyptic number.

It is an amenable number.

21211326323381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211326323381 is an equidigital number, since it uses as much as digits as its factorization.

21211326323381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 38.

Adding to 21211326323381 its reverse (18332362311212), we get a palindrome (39543688634593).

The spelling of 21211326323381 in words is "twenty-one trillion, two hundred eleven billion, three hundred twenty-six million, three hundred twenty-three thousand, three hundred eighty-one".