12531440 has 60 divisors (see below), whose sum is σ = 30290472. Its totient is φ = 4821120.

The previous prime is 12531437. The next prime is 12531443. The reversal of 12531440 is 4413521.

It is an interprime number because it is at equal distance from previous prime (12531437) and next prime (12531443).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12531443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 76799 + ... + 76961.

Almost surely, 2^12531440 is an apocalyptic number.

12531440 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 12531440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15145236).

12531440 is an abundant number, since it is smaller than the sum of its proper divisors (17759032).

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

12531440 is a wasteful number, since it uses less digits than its factorization.

12531440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 12531440 is about 3539.9774010578. The cubic root of 12531440 is about 232.2738541801.

Adding to 12531440 its reverse (4413521), we get a palindrome (16944961).

The spelling of 12531440 in words is "twelve million, five hundred thirty-one thousand, four hundred forty".