18022212 has 72 divisors (see below), whose sum is σ = 49691096. Its totient is φ = 5474304.

The previous prime is 18022201. The next prime is 18022217. The reversal of 18022212 is 21222081.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1179396 + 16842816 = 1086^2 + 4104^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (18022217) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 45198 + ... + 45594.

Almost surely, 2^18022212 is an apocalyptic number.

18022212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18022212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24845548).

18022212 is an abundant number, since it is smaller than the sum of its proper divisors (31668884).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18022212 is a wasteful number, since it uses less digits than its factorization.

18022212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 18022212 is about 4245.2575893578. The cubic root of 18022212 is about 262.1818949389.

Adding to 18022212 its reverse (21222081), we get a palindrome (39244293).

The spelling of 18022212 in words is "eighteen million, twenty-two thousand, two hundred twelve".