21093 has 8 divisors (see below), whose sum is σ = 28800. Its totient is φ = 13728.

The previous prime is 21089. The next prime is 21101. The reversal of 21093 is 39012.

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

It is not a de Polignac number, because 21093 - 2² = 21089 is a prime.

It is a Curzon number.

It is a plaindrome in base 5.

It is a zygodrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193 + ... + 281.

It is an arithmetic number, because the mean of its divisors is an integer number (3600).

2²¹⁰⁹³ is an apocalyptic number.

It is an amenable number.

21093 is a deficient number, since it is larger than the sum of its proper divisors (7707).

21093 is an equidigital number, since it uses as much as digits as its factorization.

21093 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 21093 is about 145.2342934709. The cubic root of 21093 is about 27.6299087665.

It can be divided in two parts, 2109 and 3, that added together give a palindrome (2112).

The spelling of 21093 in words is "twenty-one thousand, ninety-three".