21422 has 4 divisors (see below), whose sum is σ = 32136. Its totient is φ = 10710.

The previous prime is 21419. The next prime is 21433. The reversal of 21422 is 22412.

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

It is a plaindrome in base 13.

It is a nialpdrome in base 15.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 21422.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5354 + ... + 5357.

It is an arithmetic number, because the mean of its divisors is an integer number (8034).

2²¹⁴²² is an apocalyptic number.

21422 is a deficient number, since it is larger than the sum of its proper divisors (10714).

21422 is a wasteful number, since it uses less digits than its factorization.

21422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10713.

The product of its digits is 32, while the sum is 11.

The square root of 21422 is about 146.3625635195. The cubic root of 21422 is about 27.7728216343.

Adding to 21422 its reverse (22412), we get a palindrome (43834).

Subtracting 21422 from its reverse (22412), we obtain a triangular number (990 = T₄₄).

The spelling of 21422 in words is "twenty-one thousand, four hundred twenty-two", and thus it is an iban number.