9163721 has 4 divisors (see below), whose sum is σ = 10472832. Its totient is φ = 7854612.

The previous prime is 9163717. The next prime is 9163723. The reversal of 9163721 is 1273619.

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 an emirpimes, since its reverse is a distinct semiprime: 1273619 = 61 ⋅20879.

It is a cyclic number.

It is not a de Polignac number, because 9163721 - 2² = 9163717 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9163723) 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, 654545 + ... + 654558.

It is an arithmetic number, because the mean of its divisors is an integer number (2618208).

Almost surely, 2^9163721 is an apocalyptic number.

It is an amenable number.

9163721 is a deficient number, since it is larger than the sum of its proper divisors (1309111).

9163721 is a wasteful number, since it uses less digits than its factorization.

9163721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1309110.

The product of its digits is 2268, while the sum is 29.

The square root of 9163721 is about 3027.1638541711. The cubic root of 9163721 is about 209.2621193272.

The spelling of 9163721 in words is "nine million, one hundred sixty-three thousand, seven hundred twenty-one".