21268949369 has 2 divisors, whose sum is σ = 21268949370. Its totient is φ = 21268949368.

The previous prime is 21268949329. The next prime is 21268949411. The reversal of 21268949369 is 96394986212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21081588025 + 187361344 = 145195^2 + 13688^2 .

It is a cyclic number.

It is not a de Polignac number, because 21268949369 - 2⁸ = 21268949113 is a prime.

It is a super-2 number, since 2×21268949369² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21268949329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10634474684 + 10634474685.

It is an arithmetic number, because the mean of its divisors is an integer number (10634474685).

Almost surely, 2^21268949369 is an apocalyptic number.

It is an amenable number.

21268949369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21268949369 is an equidigital number, since it uses as much as digits as its factorization.

21268949369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10077696, while the sum is 59.

The spelling of 21268949369 in words is "twenty-one billion, two hundred sixty-eight million, nine hundred forty-nine thousand, three hundred sixty-nine".