8555521 has 4 divisors (see below), whose sum is σ = 9213652. Its totient is φ = 7897392.

The previous prime is 8555507. The next prime is 8555543. The reversal of 8555521 is 1255558.

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 404496 + 8151025 = 636^2 + 2855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8555521 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (8555021) 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, 329046 + ... + 329071.

It is an arithmetic number, because the mean of its divisors is an integer number (2303413).

Almost surely, 2^8555521 is an apocalyptic number.

It is an amenable number.

8555521 is a deficient number, since it is larger than the sum of its proper divisors (658131).

8555521 is a wasteful number, since it uses less digits than its factorization.

8555521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658130.

The product of its digits is 10000, while the sum is 31.

The square root of 8555521 is about 2924.9822221682. The cubic root of 8555521 is about 204.5261392970.

The spelling of 8555521 in words is "eight million, five hundred fifty-five thousand, five hundred twenty-one".