9997729 has 4 divisors (see below), whose sum is σ = 11425984. Its totient is φ = 8569476.

The previous prime is 9997711. The next prime is 9997739. The reversal of 9997729 is 9277999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9277999 = 29 ⋅319931.

It is a cyclic number.

It is not a de Polignac number, because 9997729 - 2⁵ = 9997697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9997739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 714117 + ... + 714130.

It is an arithmetic number, because the mean of its divisors is an integer number (2856496).

Almost surely, 2^9997729 is an apocalyptic number.

It is an amenable number.

9997729 is a deficient number, since it is larger than the sum of its proper divisors (1428255).

9997729 is a wasteful number, since it uses less digits than its factorization.

9997729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1428254.

The product of its digits is 642978, while the sum is 52.

The square root of 9997729 is about 3161.9185631512. The cubic root of 9997729 is about 215.4271586978.

The spelling of 9997729 in words is "nine million, nine hundred ninety-seven thousand, seven hundred twenty-nine".