12212172 has 144 divisors (see below), whose sum is σ = 38438400. Its totient is φ = 3259872.

The previous prime is 12212159. The next prime is 12212173. The reversal of 12212172 is 27121221.

It is a happy number.

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

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12212173) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 283983 + ... + 284025.

Almost surely, 2^12212172 is an apocalyptic number.

12212172 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 12212172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19219200).

12212172 is an abundant number, since it is smaller than the sum of its proper divisors (26226228).

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

12212172 is a wasteful number, since it uses less digits than its factorization.

12212172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 78 counting only the distinct ones).

The product of its digits is 112, while the sum is 18.

The square root of 12212172 is about 3494.5918216581. The cubic root of 12212172 is about 230.2842861511.

Adding to 12212172 its reverse (27121221), we get a palindrome (39333393).

The spelling of 12212172 in words is "twelve million, two hundred twelve thousand, one hundred seventy-two".