12315218 has 4 divisors (see below), whose sum is σ = 18472830. Its totient is φ = 6157608.

The previous prime is 12315209. The next prime is 12315223. The reversal of 12315218 is 81251321.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81251321 = 257 ⋅316153.

It can be written as a sum of positive squares in only one way, i.e., 10843849 + 1471369 = 3293^2 + 1213^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12315193 and 12315202.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3078803 + ... + 3078806.

Almost surely, 2^12315218 is an apocalyptic number.

12315218 is a deficient number, since it is larger than the sum of its proper divisors (6157612).

12315218 is an equidigital number, since it uses as much as digits as its factorization.

12315218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6157611.

The product of its digits is 480, while the sum is 23.

The square root of 12315218 is about 3509.3044894965. The cubic root of 12315218 is about 230.9301838575.

Adding to 12315218 its reverse (81251321), we get a palindrome (93566539).

The spelling of 12315218 in words is "twelve million, three hundred fifteen thousand, two hundred eighteen".