21211010020381 has 2 divisors, whose sum is σ = 21211010020382. Its totient is φ = 21211010020380.

The previous prime is 21211010020331. The next prime is 21211010020393. The reversal of 21211010020381 is 18302001011212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20257830756900 + 953179263481 = 4500870^2 + 976309^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211010020381 - 2³⁵ = 21176650282013 is a prime.

It is a super-2 number, since 2×21211010020381² (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 (21211010020331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605505010190 + 10605505010191.

It is an arithmetic number, because the mean of its divisors is an integer number (10605505010191).

Almost surely, 2^{21211010020381} is an apocalyptic number.

It is an amenable number.

21211010020381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211010020381 is an equidigital number, since it uses as much as digits as its factorization.

21211010020381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 22.

Adding to 21211010020381 its reverse (18302001011212), we get a palindrome (39513011031593).

The spelling of 21211010020381 in words is "twenty-one trillion, two hundred eleven billion, ten million, twenty thousand, three hundred eighty-one".