9351721 has 4 divisors (see below), whose sum is σ = 9375444. Its totient is φ = 9328000.

The previous prime is 9351709. The next prime is 9351737. The reversal of 9351721 is 1271539.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1271539 = 71 ⋅17909.

It can be written as a sum of positive squares in 2 ways, for example, as 7502121 + 1849600 = 2739^2 + 1360^2 .

It is a cyclic number.

It is not a de Polignac number, because 9351721 - 2⁵ = 9351689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9351721.

It is not an unprimeable number, because it can be changed into a prime (9351761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11260 + ... + 12061.

It is an arithmetic number, because the mean of its divisors is an integer number (2343861).

Almost surely, 2^9351721 is an apocalyptic number.

It is an amenable number.

9351721 is a deficient number, since it is larger than the sum of its proper divisors (23723).

9351721 is a wasteful number, since it uses less digits than its factorization.

9351721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23722.

The product of its digits is 1890, while the sum is 28.

The square root of 9351721 is about 3058.0583709275. The cubic root of 9351721 is about 210.6834948347.

The spelling of 9351721 in words is "nine million, three hundred fifty-one thousand, seven hundred twenty-one".