21222012122 has 4 divisors (see below), whose sum is σ = 31833018186. Its totient is φ = 10611006060.

The previous prime is 21222012113. The next prime is 21222012127. The reversal of 21222012122 is 22121022212.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 17867401561 + 3354610561 = 133669^2 + 57919^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21222012122.

It is not an unprimeable number, because it can be changed into a prime (21222012127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5305503029 + ... + 5305503032.

Almost surely, 2^21222012122 is an apocalyptic number.

21222012122 is a deficient number, since it is larger than the sum of its proper divisors (10611006064).

21222012122 is a wasteful number, since it uses less digits than its factorization.

21222012122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10611006063.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21222012122 its reverse (22121022212), we get a palindrome (43343034334).

The spelling of 21222012122 in words is "twenty-one billion, two hundred twenty-two million, twelve thousand, one hundred twenty-two".