9899791 has 4 divisors (see below), whose sum is σ = 10799784. Its totient is φ = 8999800.

The previous prime is 9899789. The next prime is 9899809. The reversal of 9899791 is 1979989.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1979989 = 11 ⋅179999.

It is a cyclic number.

It is not a de Polignac number, because 9899791 - 2¹ = 9899789 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9899731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 449980 + ... + 450001.

It is an arithmetic number, because the mean of its divisors is an integer number (2699946).

Almost surely, 2^9899791 is an apocalyptic number.

9899791 is a deficient number, since it is larger than the sum of its proper divisors (899993).

9899791 is a wasteful number, since it uses less digits than its factorization.

9899791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899992.

The product of its digits is 367416, while the sum is 52.

The square root of 9899791 is about 3146.3933320550. The cubic root of 9899791 is about 214.7214058781.

The spelling of 9899791 in words is "nine million, eight hundred ninety-nine thousand, seven hundred ninety-one".