21268949329 has 2 divisors, whose sum is σ = 21268949330. Its totient is φ = 21268949328.

The previous prime is 21268949323. The next prime is 21268949369. The reversal of 21268949329 is 92394986212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18889753600 + 2379195729 = 137440^2 + 48777^2 .

It is a cyclic number.

It is not a de Polignac number, because 21268949329 - 2¹⁹ = 21268425041 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21268949329.

It is not a weakly prime, because it can be changed into another prime (21268949323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10634474664 + 10634474665.

It is an arithmetic number, because the mean of its divisors is an integer number (10634474665).

Almost surely, 2^21268949329 is an apocalyptic number.

It is an amenable number.

21268949329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21268949329 is an equidigital number, since it uses as much as digits as its factorization.

21268949329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3359232, while the sum is 55.

The spelling of 21268949329 in words is "twenty-one billion, two hundred sixty-eight million, nine hundred forty-nine thousand, three hundred twenty-nine".