8366521 has 4 divisors (see below), whose sum is σ = 8381044. Its totient is φ = 8352000.

The previous prime is 8366489. The next prime is 8366573. The reversal of 8366521 is 1256638.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1256638 = 2 ⋅628319.

It can be written as a sum of positive squares in 2 ways, for example, as 6071296 + 2295225 = 2464^2 + 1515^2 .

It is a cyclic number.

It is not a de Polignac number, because 8366521 - 2⁵ = 8366489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8366591) 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, 6360 + ... + 7561.

It is an arithmetic number, because the mean of its divisors is an integer number (2095261).

Almost surely, 2^8366521 is an apocalyptic number.

It is an amenable number.

8366521 is a deficient number, since it is larger than the sum of its proper divisors (14523).

8366521 is a wasteful number, since it uses less digits than its factorization.

8366521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14522.

The product of its digits is 8640, while the sum is 31.

The square root of 8366521 is about 2892.4939066487. The cubic root of 8366521 is about 203.0088488139.

Subtracting from 8366521 its product of digits (8640), we obtain a square (8357881 = 2891²).

The spelling of 8366521 in words is "eight million, three hundred sixty-six thousand, five hundred twenty-one".