21234 has 8 divisors (see below), whose sum is σ = 42480. Its totient is φ = 7076.

The previous prime is 21227. The next prime is 21247. The reversal of 21234 is 43212.

21234 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

21234 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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

21234 is an admirable number.

It is a super-3 number, since 3×21234³ = 28722133322712, which contains 333 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a nialpdrome in base 13.

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, 1764 + ... + 1775.

It is an arithmetic number, because the mean of its divisors is an integer number (5310).

2²¹²³⁴ is an apocalyptic number.

21234 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 (21240).

21234 is a wasteful number, since it uses less digits than its factorization.

21234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3544.

The product of its digits is 48, while the sum is 12.

The square root of 21234 is about 145.7189074897. The cubic root of 21234 is about 27.6913378103.

Adding to 21234 its reverse (43212), we get a palindrome (64446).

The spelling of 21234 in words is "twenty-one thousand, two hundred thirty-four".