8381521 has 4 divisors (see below), whose sum is σ = 8418672. Its totient is φ = 8344372.

The previous prime is 8381497. The next prime is 8381531. The reversal of 8381521 is 1251838.

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.

It is a cyclic number.

It is not a de Polignac number, because 8381521 - 2⁷ = 8381393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8381521.

It is not an unprimeable number, because it can be changed into a prime (8381531) 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, 18235 + ... + 18688.

It is an arithmetic number, because the mean of its divisors is an integer number (2104668).

Almost surely, 2^8381521 is an apocalyptic number.

It is an amenable number.

8381521 is a deficient number, since it is larger than the sum of its proper divisors (37151).

8381521 is a wasteful number, since it uses less digits than its factorization.

8381521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37150.

The product of its digits is 1920, while the sum is 28.

The square root of 8381521 is about 2895.0856636721. The cubic root of 8381521 is about 203.1300985229.

The spelling of 8381521 in words is "eight million, three hundred eighty-one thousand, five hundred twenty-one".