21446 has 4 divisors (see below), whose sum is σ = 32172. Its totient is φ = 10722.

The previous prime is 21433. The next prime is 21467. The reversal of 21446 is 64412.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

21446 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5360 + ... + 5363.

It is an arithmetic number, because the mean of its divisors is an integer number (8043).

2²¹⁴⁴⁶ is an apocalyptic number.

21446 is a deficient number, since it is larger than the sum of its proper divisors (10726).

21446 is a wasteful number, since it uses less digits than its factorization.

21446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10725.

The product of its digits is 192, while the sum is 17.

The square root of 21446 is about 146.4445287472. Note that the first 3 decimals coincide. The cubic root of 21446 is about 27.7831894641.

Adding to 21446 its reverse (64412), we get a palindrome (85858).

The spelling of 21446 in words is "twenty-one thousand, four hundred forty-six".