21222122 has 16 divisors (see below), whose sum is σ = 32535432. Its totient is φ = 10379520.

The previous prime is 21222043. The next prime is 21222143. The reversal of 21222122 is 22122212.

It can be written as a sum of positive squares in 4 ways, for example, as 20079361 + 1142761 = 4481^2 + 1069^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21222097 and 21222106.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19472 + ... + 20532.

Almost surely, 2^21222122 is an apocalyptic number.

21222122 is a deficient number, since it is larger than the sum of its proper divisors (11313310).

21222122 is a wasteful number, since it uses less digits than its factorization.

21222122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273.

The product of its digits is 64, while the sum is 14.

The square root of 21222122 is about 4606.7474426107. The cubic root of 21222122 is about 276.8617346599.

Adding to 21222122 its reverse (22122212), we get a palindrome (43344334).

It can be divided in two parts, 2122212 and 2, that multiplied together give a palindrome (4244424).

The spelling of 21222122 in words is "twenty-one million, two hundred twenty-two thousand, one hundred twenty-two".