21121311134321 has 2 divisors, whose sum is σ = 21121311134322. Its totient is φ = 21121311134320.

The previous prime is 21121311134309. The next prime is 21121311134353. The reversal of 21121311134321 is 12343111312112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14758935493696 + 6362375640625 = 3841736^2 + 2522375^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121311134321 - 2²⁶ = 21121244025457 is a prime.

It is a super-2 number, since 2×21121311134321² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121311134621) 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, 10560655567160 + 10560655567161.

It is an arithmetic number, because the mean of its divisors is an integer number (10560655567161).

Almost surely, 2^{21121311134321} is an apocalyptic number.

It is an amenable number.

21121311134321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121311134321 is an equidigital number, since it uses as much as digits as its factorization.

21121311134321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 26.

Adding to 21121311134321 its reverse (12343111312112), we get a palindrome (33464422446433).

The spelling of 21121311134321 in words is "twenty-one trillion, one hundred twenty-one billion, three hundred eleven million, one hundred thirty-four thousand, three hundred twenty-one".