21759469729 has 2 divisors, whose sum is σ = 21759469730. Its totient is φ = 21759469728.

The previous prime is 21759469703. The next prime is 21759469733. The reversal of 21759469729 is 92796495712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21331186704 + 428283025 = 146052^2 + 20695^2 .

It is a cyclic number.

It is not a de Polignac number, because 21759469729 - 2²⁷ = 21625252001 is a prime.

It is not a weakly prime, because it can be changed into another prime (21759469789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10879734864 + 10879734865.

It is an arithmetic number, because the mean of its divisors is an integer number (10879734865).

Almost surely, 2^21759469729 is an apocalyptic number.

It is an amenable number.

21759469729 is a deficient number, since it is larger than the sum of its proper divisors (1).

21759469729 is an equidigital number, since it uses as much as digits as its factorization.

21759469729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17146080, while the sum is 61.

The spelling of 21759469729 in words is "twenty-one billion, seven hundred fifty-nine million, four hundred sixty-nine thousand, seven hundred twenty-nine".