99021 has 8 divisors (see below), whose sum is σ = 142240. Its totient is φ = 60912.

The previous prime is 99017. The next prime is 99023. The reversal of 99021 is 12099.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 99021 - 2² = 99017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1231 + ... + 1308.

It is an arithmetic number, because the mean of its divisors is an integer number (17780).

2⁹⁹⁰²¹ is an apocalyptic number.

It is an amenable number.

99021 is a deficient number, since it is larger than the sum of its proper divisors (43219).

99021 is a wasteful number, since it uses less digits than its factorization.

99021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2555.

The product of its (nonzero) digits is 162, while the sum is 21.

The square root of 99021 is about 314.6760238722. The cubic root of 99021 is about 46.2639208156.

The spelling of 99021 in words is "ninety-nine thousand, twenty-one".