21044403769 has 2 divisors, whose sum is σ = 21044403770. Its totient is φ = 21044403768.

The previous prime is 21044403767. The next prime is 21044403773. The reversal of 21044403769 is 96730444012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10834311744 + 10210092025 = 104088^2 + 101045^2 .

It is a cyclic number.

It is not a de Polignac number, because 21044403769 - 2¹ = 21044403767 is a prime.

It is a super-2 number, since 2×21044403769² (a number of 21 digits) contains 22 as substring.

Together with 21044403767, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21044403761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10522201884 + 10522201885.

It is an arithmetic number, because the mean of its divisors is an integer number (10522201885).

Almost surely, 2^21044403769 is an apocalyptic number.

It is an amenable number.

21044403769 is a deficient number, since it is larger than the sum of its proper divisors (1).

21044403769 is an equidigital number, since it uses as much as digits as its factorization.

21044403769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 40.

The spelling of 21044403769 in words is "twenty-one billion, forty-four million, four hundred three thousand, seven hundred sixty-nine".