12131440 has 20 divisors (see below), whose sum is σ = 28205784. Its totient is φ = 4852544.

The previous prime is 12131437. The next prime is 12131473. The reversal of 12131440 is 4413121.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 75742 + ... + 75901.

Almost surely, 2^12131440 is an apocalyptic number.

12131440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12131440 is an abundant number, since it is smaller than the sum of its proper divisors (16074344).

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

12131440 is a wasteful number, since it uses less digits than its factorization.

12131440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151656 (or 151650 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 12131440 is about 3483.0216766480. The cubic root of 12131440 is about 229.7757107774.

Adding to 12131440 its reverse (4413121), we get a palindrome (16544561).

The spelling of 12131440 in words is "twelve million, one hundred thirty-one thousand, four hundred forty".