8423521 has 4 divisors (see below), whose sum is σ = 8477332. Its totient is φ = 8369712.

The previous prime is 8423507. The next prime is 8423549. The reversal of 8423521 is 1253248.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1347921 + 7075600 = 1161^2 + 2660^2 .

It is a cyclic number.

It is not a de Polignac number, because 8423521 - 2²³ = 34913 is a prime.

It is a d-powerful number, because it can be written as 8⁵ + 4³ + 2¹¹ + 3³ + 5 + 2²³ + 1 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8423321) 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, 26670 + ... + 26983.

It is an arithmetic number, because the mean of its divisors is an integer number (2119333).

Almost surely, 2^8423521 is an apocalyptic number.

It is an amenable number.

8423521 is a deficient number, since it is larger than the sum of its proper divisors (53811).

8423521 is a wasteful number, since it uses less digits than its factorization.

8423521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53810.

The product of its digits is 1920, while the sum is 25.

The square root of 8423521 is about 2902.3302706618. The cubic root of 8423521 is about 203.4688299306.

Adding to 8423521 its reverse (1253248), we get a palindrome (9676769).

The spelling of 8423521 in words is "eight million, four hundred twenty-three thousand, five hundred twenty-one".