12517840 has 40 divisors (see below), whose sum is σ = 29897640. Its totient is φ = 4870656.

The previous prime is 12517829. The next prime is 12517847. The reversal of 12517840 is 4871521.

It can be written as a sum of positive squares in 4 ways, for example, as 7817616 + 4700224 = 2796^2 + 2168^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 12517799 and 12517808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12517847) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 846 + ... + 5074.

It is an arithmetic number, because the mean of its divisors is an integer number (747441).

Almost surely, 2^12517840 is an apocalyptic number.

12517840 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 12517840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14948820).

12517840 is an abundant number, since it is smaller than the sum of its proper divisors (17379800).

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

12517840 is a wasteful number, since it uses less digits than its factorization.

12517840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4279 (or 4273 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 12517840 is about 3538.0559633788. The cubic root of 12517840 is about 232.1897971239.

The spelling of 12517840 in words is "twelve million, five hundred seventeen thousand, eight hundred forty".