22218172 has 12 divisors (see below), whose sum is σ = 39429936. Its totient is φ = 10952480.

The previous prime is 22218137. The next prime is 22218179. The reversal of 22218172 is 27181222.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22218179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38833 + ... + 39400.

It is an arithmetic number, because the mean of its divisors is an integer number (3285828).

Almost surely, 2^22218172 is an apocalyptic number.

It is an amenable number.

22218172 is a deficient number, since it is larger than the sum of its proper divisors (17211764).

22218172 is a wasteful number, since it uses less digits than its factorization.

22218172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78308 (or 78306 counting only the distinct ones).

The product of its digits is 896, while the sum is 25.

The square root of 22218172 is about 4713.6155973944. The cubic root of 22218172 is about 281.1271402808.

Adding to 22218172 its reverse (27181222), we get a palindrome (49399394).

It can be divided in two parts, 2 and 2218172, that multiplied together give a palindrome (4436344).

The spelling of 22218172 in words is "twenty-two million, two hundred eighteen thousand, one hundred seventy-two".