9213521 has 4 divisors (see below), whose sum is σ = 9224292. Its totient is φ = 9202752.

The previous prime is 9213517. The next prime is 9213527. The reversal of 9213521 is 1253129.

9213521 is digitally balanced in base 3, 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: 1253129 = 211 ⋅5939.

It can be written as a sum of positive squares in 2 ways, for example, as 2265025 + 6948496 = 1505^2 + 2636^2 .

It is a cyclic number.

It is not a de Polignac number, because 9213521 - 2² = 9213517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9213527) 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, 3980 + ... + 5853.

It is an arithmetic number, because the mean of its divisors is an integer number (2306073).

Almost surely, 2^9213521 is an apocalyptic number.

It is an amenable number.

9213521 is a deficient number, since it is larger than the sum of its proper divisors (10771).

9213521 is an equidigital number, since it uses as much as digits as its factorization.

9213521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10770.

The product of its digits is 540, while the sum is 23.

The square root of 9213521 is about 3035.3782301387. The cubic root of 9213521 is about 209.6405111880.

The spelling of 9213521 in words is "nine million, two hundred thirteen thousand, five hundred twenty-one".