9999729 has 6 divisors (see below), whose sum is σ = 14444066. Its totient is φ = 6666480.

The previous prime is 9999713. The next prime is 9999739. The reversal of 9999729 is 9279999.

It can be written as a sum of positive squares in only one way, i.e., 5475600 + 4524129 = 2340^2 + 2127^2 .

It is not a de Polignac number, because 9999729 - 2⁴ = 9999713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9999739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 555532 + ... + 555549.

Almost surely, 2^9999729 is an apocalyptic number.

It is an amenable number.

9999729 is a deficient number, since it is larger than the sum of its proper divisors (4444337).

9999729 is a wasteful number, since it uses less digits than its factorization.

9999729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111087 (or 1111084 counting only the distinct ones).

The product of its digits is 826686, while the sum is 54.

The square root of 9999729 is about 3162.2348110158. The cubic root of 9999729 is about 215.4415228129.

The spelling of 9999729 in words is "nine million, nine hundred ninety-nine thousand, seven hundred twenty-nine".