21122 has 8 divisors (see below), whose sum is σ = 32400. Its totient is φ = 10324.

The previous prime is 21121. The next prime is 21139. The reversal of 21122 is 22112.

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

It is a super-2 number, since 2×21122² = 892277768, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (21121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29 + ... + 207.

It is an arithmetic number, because the mean of its divisors is an integer number (4050).

2²¹¹²² is an apocalyptic number.

21122 is a deficient number, since it is larger than the sum of its proper divisors (11278).

21122 is a wasteful number, since it uses less digits than its factorization.

21122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240.

The product of its digits is 8, while the sum is 8.

The square root of 21122 is about 145.3340978573. The cubic root of 21122 is about 27.6425654207.

Adding to 21122 its reverse (22112), we get a palindrome (43234).

Subtracting 21122 from its reverse (22112), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 2112 and 2, that multiplied together give a palindrome (4224).

The spelling of 21122 in words is "twenty-one thousand, one hundred twenty-two", and thus it is an iban number.