21262 has 4 divisors (see below), whose sum is σ = 31896. Its totient is φ = 10630.

The previous prime is 21247. The next prime is 21269. The reversal of 21262 is 26212.

It is a happy number.

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

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21269) by changing a digit.

21262 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5314 + ... + 5317.

It is an arithmetic number, because the mean of its divisors is an integer number (7974).

2²¹²⁶² is an apocalyptic number.

21262 is a deficient number, since it is larger than the sum of its proper divisors (10634).

21262 is a wasteful number, since it uses less digits than its factorization.

21262 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10633.

The product of its digits is 48, while the sum is 13.

The square root of 21262 is about 145.8149512224. The cubic root of 21262 is about 27.7035040987.

Adding to 21262 its reverse (26212), we get a palindrome (47474).

Subtracting 21262 from its reverse (26212), we obtain a triangular number (4950 = T₉₉).

The spelling of 21262 in words is "twenty-one thousand, two hundred sixty-two".