8999521 has 4 divisors (see below), whose sum is σ = 9473200. Its totient is φ = 8525844.

The previous prime is 8999519. The next prime is 8999527. The reversal of 8999521 is 1259998.

8999521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 8999521 - 2¹ = 8999519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8999527) 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, 236811 + ... + 236848.

It is an arithmetic number, because the mean of its divisors is an integer number (2368300).

Almost surely, 2^8999521 is an apocalyptic number.

It is an amenable number.

8999521 is a deficient number, since it is larger than the sum of its proper divisors (473679).

8999521 is a wasteful number, since it uses less digits than its factorization.

8999521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473678.

The product of its digits is 58320, while the sum is 43.

The square root of 8999521 is about 2999.9201656044. The cubic root of 8999521 is about 208.0046920169.

The spelling of 8999521 in words is "eight million, nine hundred ninety-nine thousand, five hundred twenty-one".