21152206334549 has 2 divisors, whose sum is σ = 21152206334550. Its totient is φ = 21152206334548.

The previous prime is 21152206334521. The next prime is 21152206334551. The reversal of 21152206334549 is 94543360225112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21078612411025 + 73593923524 = 4591145^2 + 271282^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21152206334549 is a prime.

It is a super-2 number, since 2×21152206334549² (a number of 27 digits) contains 22 as substring.

Together with 21152206334551, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21152206334579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10576103167274 + 10576103167275.

It is an arithmetic number, because the mean of its divisors is an integer number (10576103167275).

Almost surely, 2^{21152206334549} is an apocalyptic number.

It is an amenable number.

21152206334549 is a deficient number, since it is larger than the sum of its proper divisors (1).

21152206334549 is an equidigital number, since it uses as much as digits as its factorization.

21152206334549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1555200, while the sum is 47.

The spelling of 21152206334549 in words is "twenty-one trillion, one hundred fifty-two billion, two hundred six million, three hundred thirty-four thousand, five hundred forty-nine".