729800009 has 2 divisors, whose sum is σ = 729800010. Its totient is φ = 729800008.

The previous prime is 729799997. The next prime is 729800023. The reversal of 729800009 is 900008927.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 729270025 + 529984 = 27005^2 + 728^2 .

It is an emirp because it is prime and its reverse (900008927) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-729800009 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (729800059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364900004 + 364900005.

It is an arithmetic number, because the mean of its divisors is an integer number (364900005).

Almost surely, 2^729800009 is an apocalyptic number.

It is an amenable number.

729800009 is a deficient number, since it is larger than the sum of its proper divisors (1).

729800009 is an equidigital number, since it uses as much as digits as its factorization.

729800009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 729800009 is about 27014.8109191976. The cubic root of 729800009 is about 900.3291014541.

The spelling of 729800009 in words is "seven hundred twenty-nine million, eight hundred thousand, nine".