99221 has 4 divisors (see below), whose sum is σ = 99852. Its totient is φ = 98592.

The previous prime is 99191. The next prime is 99223. The reversal of 99221 is 12299.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2500 + 96721 = 50^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 99221 - 2¹⁴ = 82837 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99223) 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, 155 + ... + 471.

It is an arithmetic number, because the mean of its divisors is an integer number (24963).

2⁹⁹²²¹ is an apocalyptic number.

It is an amenable number.

99221 is a deficient number, since it is larger than the sum of its proper divisors (631).

99221 is a wasteful number, since it uses less digits than its factorization.

99221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630.

The product of its digits is 324, while the sum is 23.

The square root of 99221 is about 314.9936507297. The cubic root of 99221 is about 46.2950474172.

The spelling of 99221 in words is "ninety-nine thousand, two hundred twenty-one".