9021 has 8 divisors (see below), whose sum is σ = 12544. Its totient is φ = 5760.

The previous prime is 9013. The next prime is 9029. The reversal of 9021 is 1209.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (9013) and next prime (9029).

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

It is not a de Polignac number, because 9021 - 2³ = 9013 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 9 and base 16.

It is a junction number, because it is equal to n+sod(n) for n = 8988 and 9006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9029) 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, 45 + ... + 141.

It is an arithmetic number, because the mean of its divisors is an integer number (1568).

2⁹⁰²¹ is an apocalyptic number.

It is an amenable number.

9021 is a deficient number, since it is larger than the sum of its proper divisors (3523).

9021 is a wasteful number, since it uses less digits than its factorization.

9021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 9021 is about 94.9789450352. The cubic root of 9021 is about 20.8170040933.

Subtracting from 9021 its sum of digits (12), we obtain a palindrome (9009).

It can be divided in two parts, 902 and 1, that added together give a triangular number (903 = T₄₂).

The spelling of 9021 in words is "nine thousand, twenty-one".