It is a happy number.
22222222 is nontrivially palindromic in base 10.
It is a nude number because it is divisible by every one of its digits.
22222222 is a nontrivial repdigit in base 10.
It is a plaindrome in base 10.
It is a nialpdrome in base 10.
It is a zygodrome in base 10.
It is a congruent number.
Almost surely, 222222222 is an apocalyptic number.
22222222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.
22222222 is a wasteful number, since it uses less digits than its factorization.
22222222 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 324.
The square root of 22222222 is about 4714.0451843401. The cubic root of 22222222 is about 281.1442208301.
The spelling of 22222222 in words is "twenty-two million, two hundred twenty-two thousand, two hundred twenty-two".