21153 has 8 divisors (see below), whose sum is σ = 30816. Its totient is φ = 12800.

The previous prime is 21149. The next prime is 21157. The reversal of 21153 is 35112.

It is an interprime number because it is at equal distance from previous prime (21149) and next prime (21157).

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

It is a cyclic number.

It is not a de Polignac number, because 21153 - 2² = 21149 is a prime.

It is a Curzon number.

21153 is a lucky number.

It is a plaindrome in base 14.

It is a nialpdrome in base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 21153.

It is not an unprimeable number, because it can be changed into a prime (21157) 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, 288 + ... + 353.

It is an arithmetic number, because the mean of its divisors is an integer number (3852).

2²¹¹⁵³ is an apocalyptic number.

It is an amenable number.

21153 is a deficient number, since it is larger than the sum of its proper divisors (9663).

21153 is a wasteful number, since it uses less digits than its factorization.

21153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655.

The product of its digits is 30, while the sum is 12.

The square root of 21153 is about 145.4407095692. The cubic root of 21153 is about 27.6560821433.

Adding to 21153 its reverse (35112), we get a palindrome (56265).

The spelling of 21153 in words is "twenty-one thousand, one hundred fifty-three".