9750721 has 4 divisors (see below), whose sum is σ = 10014292. Its totient is φ = 9487152.

The previous prime is 9750659. The next prime is 9750737. The reversal of 9750721 is 1270579.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4410000 + 5340721 = 2100^2 + 2311^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9750721 is a prime.

It is a Duffinian number.

9750721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (9750821) 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, 131730 + ... + 131803.

It is an arithmetic number, because the mean of its divisors is an integer number (2503573).

Almost surely, 2^9750721 is an apocalyptic number.

It is an amenable number.

9750721 is a deficient number, since it is larger than the sum of its proper divisors (263571).

9750721 is a wasteful number, since it uses less digits than its factorization.

9750721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263570.

The product of its (nonzero) digits is 4410, while the sum is 31.

The square root of 9750721 is about 3122.6144494638. The cubic root of 9750721 is about 213.6381999156.

The spelling of 9750721 in words is "nine million, seven hundred fifty thousand, seven hundred twenty-one".