13031218 has 4 divisors (see below), whose sum is σ = 19546830. Its totient is φ = 6515608.

The previous prime is 13031201. The next prime is 13031233. The reversal of 13031218 is 81213031.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81213031 = 1087 ⋅74713.

It can be written as a sum of positive squares in only one way, i.e., 7800849 + 5230369 = 2793^2 + 2287^2 .

It is a junction number, because it is equal to n+sod(n) for n = 13031195 and 13031204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3257803 + ... + 3257806.

Almost surely, 2^13031218 is an apocalyptic number.

13031218 is a deficient number, since it is larger than the sum of its proper divisors (6515612).

13031218 is an equidigital number, since it uses as much as digits as its factorization.

13031218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6515611.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 13031218 is about 3609.8778372682. The cubic root of 13031218 is about 235.3215336118.

Adding to 13031218 its reverse (81213031), we get a palindrome (94244249).

The spelling of 13031218 in words is "thirteen million, thirty-one thousand, two hundred eighteen".