21354 has 8 divisors (see below), whose sum is σ = 42720. Its totient is φ = 7116.

The previous prime is 21347. The next prime is 21377. The reversal of 21354 is 45312.

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

21354 is an admirable number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1774 + ... + 1785.

It is an arithmetic number, because the mean of its divisors is an integer number (5340).

2²¹³⁵⁴ is an apocalyptic number.

21354 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21360).

21354 is a wasteful number, since it uses less digits than its factorization.

21354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3564.

The product of its digits is 120, while the sum is 15.

The square root of 21354 is about 146.1300790392. The cubic root of 21354 is about 27.7434040000.

Adding to 21354 its reverse (45312), we get a palindrome (66666).

The spelling of 21354 in words is "twenty-one thousand, three hundred fifty-four".