8723521 has 2 divisors, whose sum is σ = 8723522. Its totient is φ = 8723520.

The previous prime is 8723497. The next prime is 8723531. The reversal of 8723521 is 1253278.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8042896 + 680625 = 2836^2 + 825^2 .

It is a cyclic number.

It is not a de Polignac number, because 8723521 - 2¹¹ = 8721473 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8723521.

It is not a weakly prime, because it can be changed into another prime (8723531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4361760 + 4361761.

It is an arithmetic number, because the mean of its divisors is an integer number (4361761).

Almost surely, 2^8723521 is an apocalyptic number.

It is an amenable number.

8723521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8723521 is an equidigital number, since it uses as much as digits as its factorization.

8723521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 28.

The square root of 8723521 is about 2953.5607324042. The cubic root of 8723521 is about 205.8561930315.

Adding to 8723521 its reverse (1253278), we get a palindrome (9976799).

The spelling of 8723521 in words is "eight million, seven hundred twenty-three thousand, five hundred twenty-one".