12172320 has 144 divisors (see below), whose sum is σ = 42456960. Its totient is φ = 3174912.

The previous prime is 12172309. The next prime is 12172327. The reversal of 12172320 is 2327121.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a junction number, because it is equal to n+sod(n) for n = 12172293 and 12172302.

It is not an unprimeable number, because it can be changed into a prime (12172327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 113707 + ... + 113813.

It is an arithmetic number, because the mean of its divisors is an integer number (294840).

Almost surely, 2^12172320 is an apocalyptic number.

12172320 is a gapful number since it is divisible by the number (10) 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 12172320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21228480).

12172320 is an abundant number, since it is smaller than the sum of its proper divisors (30284640).

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

12172320 is a wasteful number, since it uses less digits than its factorization.

12172320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207 (or 196 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 12172320 is about 3488.8852087737. The cubic root of 12172320 is about 230.0335174846.

Adding to 12172320 its reverse (2327121), we get a palindrome (14499441).

The spelling of 12172320 in words is "twelve million, one hundred seventy-two thousand, three hundred twenty".