9249721 has 4 divisors (see below), whose sum is σ = 9961252. Its totient is φ = 8538192.

The previous prime is 9249707. The next prime is 9249731. The reversal of 9249721 is 1279429.

It is a happy number.

9249721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1279429 = 557 ⋅2297.

It can be written as a sum of positive squares in 2 ways, for example, as 4562496 + 4687225 = 2136^2 + 2165^2 .

It is not a de Polignac number, because 9249721 - 2⁵ = 9249689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9249701) 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, 355746 + ... + 355771.

It is an arithmetic number, because the mean of its divisors is an integer number (2490313).

Almost surely, 2^9249721 is an apocalyptic number.

It is an amenable number.

9249721 is a deficient number, since it is larger than the sum of its proper divisors (711531).

9249721 is a wasteful number, since it uses less digits than its factorization.

9249721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711530.

The product of its digits is 9072, while the sum is 34.

The square root of 9249721 is about 3041.3353974858. The cubic root of 9249721 is about 209.9147121541.

The spelling of 9249721 in words is "nine million, two hundred forty-nine thousand, seven hundred twenty-one".