12138220 has 48 divisors (see below), whose sum is σ = 26812800. Its totient is φ = 4610304.

The previous prime is 12138209. The next prime is 12138223. The reversal of 12138220 is 2283121.

It is not an unprimeable number, because it can be changed into a prime (12138223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34606 + ... + 34954.

It is an arithmetic number, because the mean of its divisors is an integer number (558600).

Almost surely, 2^12138220 is an apocalyptic number.

12138220 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 12138220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13406400).

12138220 is an abundant number, since it is smaller than the sum of its proper divisors (14674580).

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

12138220 is a wasteful number, since it uses less digits than its factorization.

12138220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 440 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 12138220 is about 3483.9948335209. The cubic root of 12138220 is about 229.8185083675.

The spelling of 12138220 in words is "twelve million, one hundred thirty-eight thousand, two hundred twenty".