18031208 has 32 divisors (see below), whose sum is σ = 36597960. Its totient is φ = 8279040.

The previous prime is 18031199. The next prime is 18031217. The reversal of 18031208 is 80213081.

It is an interprime number because it is at equal distance from previous prime (18031199) and next prime (18031217).

It can be written as a sum of positive squares in 4 ways, for example, as 8655364 + 9375844 = 2942^2 + 3062^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28916 + ... + 29532.

Almost surely, 2^18031208 is an apocalyptic number.

It is an amenable number.

18031208 is an abundant number, since it is smaller than the sum of its proper divisors (18566752).

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

18031208 is a wasteful number, since it uses less digits than its factorization.

18031208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917 (or 913 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 18031208 is about 4246.3169924065. The cubic root of 18031208 is about 262.2255114125.

Adding to 18031208 its reverse (80213081), we get a palindrome (98244289).

The spelling of 18031208 in words is "eighteen million, thirty-one thousand, two hundred eight".