21220344269429 has 2 divisors, whose sum is σ = 21220344269430. Its totient is φ = 21220344269428.

The previous prime is 21220344269417. The next prime is 21220344269431. The reversal of 21220344269429 is 92496244302212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16080284460529 + 5140059808900 = 4010023^2 + 2267170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220344269429 is a prime.

Together with 21220344269431, 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 (21220344269479) 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, 10610172134714 + 10610172134715.

It is an arithmetic number, because the mean of its divisors is an integer number (10610172134715).

Almost surely, 2^{21220344269429} is an apocalyptic number.

It is an amenable number.

21220344269429 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220344269429 is an equidigital number, since it uses as much as digits as its factorization.

21220344269429 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2985984, while the sum is 50.

The spelling of 21220344269429 in words is "twenty-one trillion, two hundred twenty billion, three hundred forty-four million, two hundred sixty-nine thousand, four hundred twenty-nine".