12129440 has 72 divisors (see below), whose sum is σ = 30053268. Its totient is φ = 4623360.

The previous prime is 12129419. The next prime is 12129473. The reversal of 12129440 is 4492121.

It can be written as a sum of positive squares in 2 ways, for example, as 10679824 + 1449616 = 3268^2 + 1204^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 282059 + ... + 282101.

Almost surely, 2^12129440 is an apocalyptic number.

12129440 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 12129440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15026634).

12129440 is an abundant number, since it is smaller than the sum of its proper divisors (17923828).

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

12129440 is an equidigital number, since it uses as much as digits as its factorization.

12129440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 91 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 12129440 is about 3482.7345577865. The cubic root of 12129440 is about 229.7630830741.

The spelling of 12129440 in words is "twelve million, one hundred twenty-nine thousand, four hundred forty".