21742743617633 has 2 divisors, whose sum is σ = 21742743617634. Its totient is φ = 21742743617632.

The previous prime is 21742743617603. The next prime is 21742743617653. The reversal of 21742743617633 is 33671634724712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18422706140224 + 3320037477409 = 4292168^2 + 1822097^2 .

It is a cyclic number.

It is not a de Polignac number, because 21742743617633 - 2²⁶ = 21742676508769 is a prime.

It is a super-2 number, since 2×21742743617633² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21742743617603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10871371808816 + 10871371808817.

It is an arithmetic number, because the mean of its divisors is an integer number (10871371808817).

Almost surely, 2^{21742743617633} is an apocalyptic number.

It is an amenable number.

21742743617633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21742743617633 is an equidigital number, since it uses as much as digits as its factorization.

21742743617633 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21337344, while the sum is 56.

The spelling of 21742743617633 in words is "twenty-one trillion, seven hundred forty-two billion, seven hundred forty-three million, six hundred seventeen thousand, six hundred thirty-three".