12381840 has 120 divisors (see below), whose sum is σ = 43088760. Its totient is φ = 3182592.

The previous prime is 12381833. The next prime is 12381847. The reversal of 12381840 is 4818321.

It is an interprime number because it is at equal distance from previous prime (12381833) and next prime (12381847).

It can be written as a sum of positive squares in 4 ways, for example, as 1806336 + 10575504 = 1344^2 + 3252^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is not an unprimeable number, because it can be changed into a prime (12381847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20584 + ... + 21176.

It is an arithmetic number, because the mean of its divisors is an integer number (359073).

Almost surely, 2^12381840 is an apocalyptic number.

12381840 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 12381840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21544380).

12381840 is an abundant number, since it is smaller than the sum of its proper divisors (30706920).

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

12381840 is a wasteful number, since it uses less digits than its factorization.

12381840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641 (or 632 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 12381840 is about 3518.7838808316. The cubic root of 12381840 is about 231.3458584815.

The spelling of 12381840 in words is "twelve million, three hundred eighty-one thousand, eight hundred forty".