9617721 has 4 divisors (see below), whose sum is σ = 12823632. Its totient is φ = 6411812.

The previous prime is 9617683. The next prime is 9617723. The reversal of 9617721 is 1277169.

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.

It is a cyclic number.

It is not a de Polignac number, because 9617721 - 2⁷ = 9617593 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9617723) 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, 1602951 + ... + 1602956.

It is an arithmetic number, because the mean of its divisors is an integer number (3205908).

Almost surely, 2^9617721 is an apocalyptic number.

It is an amenable number.

9617721 is a deficient number, since it is larger than the sum of its proper divisors (3205911).

9617721 is a wasteful number, since it uses less digits than its factorization.

9617721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3205910.

The product of its digits is 5292, while the sum is 33.

The square root of 9617721 is about 3101.2450725475. The cubic root of 9617721 is about 212.6624068726.

The spelling of 9617721 in words is "nine million, six hundred seventeen thousand, seven hundred twenty-one".