8387521 has 4 divisors (see below), whose sum is σ = 8395200. Its totient is φ = 8379844.

The previous prime is 8387513. The next prime is 8387539. The reversal of 8387521 is 1257838.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 8387521 - 2³ = 8387513 is a prime.

It is a Duffinian number.

8387521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8387501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1861 + ... + 4498.

It is an arithmetic number, because the mean of its divisors is an integer number (2098800).

Almost surely, 2^8387521 is an apocalyptic number.

It is an amenable number.

8387521 is a deficient number, since it is larger than the sum of its proper divisors (7679).

8387521 is a wasteful number, since it uses less digits than its factorization.

8387521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7678.

The product of its digits is 13440, while the sum is 34.

The square root of 8387521 is about 2896.1217170554. The cubic root of 8387521 is about 203.1785579008.

The spelling of 8387521 in words is "eight million, three hundred eighty-seven thousand, five hundred twenty-one".