729698561 has 2 divisors, whose sum is σ = 729698562. Its totient is φ = 729698560.

The previous prime is 729698527. The next prime is 729698581. The reversal of 729698561 is 165896927.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 727326961 + 2371600 = 26969^2 + 1540^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-729698561 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (729698581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364849280 + 364849281.

It is an arithmetic number, because the mean of its divisors is an integer number (364849281).

Almost surely, 2^729698561 is an apocalyptic number.

It is an amenable number.

729698561 is a deficient number, since it is larger than the sum of its proper divisors (1).

729698561 is an equidigital number, since it uses as much as digits as its factorization.

729698561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 53.

The square root of 729698561 is about 27012.9332172572. The cubic root of 729698561 is about 900.2873818880.

The spelling of 729698561 in words is "seven hundred twenty-nine million, six hundred ninety-eight thousand, five hundred sixty-one".