21742948769 has 2 divisors, whose sum is σ = 21742948770. Its totient is φ = 21742948768.

The previous prime is 21742948697. The next prime is 21742948793. The reversal of 21742948769 is 96784924712.

Together with previous prime (21742948697) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21466059169 + 276889600 = 146513^2 + 16640^2 .

It is a cyclic number.

It is not a de Polignac number, because 21742948769 - 2¹⁶ = 21742883233 is a prime.

It is a super-2 number, since 2×21742948769² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21742948069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10871474384 + 10871474385.

It is an arithmetic number, because the mean of its divisors is an integer number (10871474385).

Almost surely, 2^21742948769 is an apocalyptic number.

It is an amenable number.

21742948769 is a deficient number, since it is larger than the sum of its proper divisors (1).

21742948769 is an equidigital number, since it uses as much as digits as its factorization.

21742948769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12192768, while the sum is 59.

The spelling of 21742948769 in words is "twenty-one billion, seven hundred forty-two million, nine hundred forty-eight thousand, seven hundred sixty-nine".