12515218 has 4 divisors (see below), whose sum is σ = 18772830. Its totient is φ = 6257608.

The previous prime is 12515203. The next prime is 12515311. The reversal of 12515218 is 81251521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81251521 = 13 ⋅6250117.

It can be written as a sum of positive squares in only one way, i.e., 11854249 + 660969 = 3443^2 + 813^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12515192 and 12515201.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3128803 + ... + 3128806.

Almost surely, 2^12515218 is an apocalyptic number.

12515218 is a deficient number, since it is larger than the sum of its proper divisors (6257612).

12515218 is an equidigital number, since it uses as much as digits as its factorization.

12515218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6257611.

The product of its digits is 800, while the sum is 25.

The square root of 12515218 is about 3537.6854015019. The cubic root of 12515218 is about 232.1735844184.

Adding to 12515218 its reverse (81251521), we get a palindrome (93766739).

The spelling of 12515218 in words is "twelve million, five hundred fifteen thousand, two hundred eighteen".