729568661 has 2 divisors, whose sum is σ = 729568662. Its totient is φ = 729568660.

The previous prime is 729568633. The next prime is 729568681. The reversal of 729568661 is 166865927.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 729540100 + 28561 = 27010^2 + 169^2 .

It is a cyclic number.

It is not a de Polignac number, because 729568661 - 2¹⁴ = 729552277 is a prime.

It is a super-2 number, since 2×729568661² = 1064540862226665842, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (729568681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364784330 + 364784331.

It is an arithmetic number, because the mean of its divisors is an integer number (364784331).

Almost surely, 2^729568661 is an apocalyptic number.

It is an amenable number.

729568661 is a deficient number, since it is larger than the sum of its proper divisors (1).

729568661 is an equidigital number, since it uses as much as digits as its factorization.

729568661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1088640, while the sum is 50.

The square root of 729568661 is about 27010.5287064137. The cubic root of 729568661 is about 900.2339560500.

The spelling of 729568661 in words is "seven hundred twenty-nine million, five hundred sixty-eight thousand, six hundred sixty-one".