9937721 has 4 divisors (see below), whose sum is σ = 9945744. Its totient is φ = 9929700.

The previous prime is 9937699. The next prime is 9937729. The reversal of 9937721 is 1277399.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1277399 = 991 ⋅1289.

It is a cyclic number.

It is not a de Polignac number, because 9937721 - 2¹⁰ = 9936697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9937729) 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, 1715 + ... + 4776.

It is an arithmetic number, because the mean of its divisors is an integer number (2486436).

Almost surely, 2^9937721 is an apocalyptic number.

It is an amenable number.

9937721 is a deficient number, since it is larger than the sum of its proper divisors (8023).

9937721 is a wasteful number, since it uses less digits than its factorization.

9937721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8022.

The product of its digits is 23814, while the sum is 38.

The square root of 9937721 is about 3152.4151059148. The cubic root of 9937721 is about 214.9952838338.

The spelling of 9937721 in words is "nine million, nine hundred thirty-seven thousand, seven hundred twenty-one".