18957218 has 12 divisors (see below), whose sum is σ = 33078582. Its totient is φ = 8124480.

The previous prime is 18957203. The next prime is 18957223. The reversal of 18957218 is 81275981.

It can be written as a sum of positive squares in only one way, i.e., 18774889 + 182329 = 4333^2 + 427^2 .

It is a super-2 number, since 2×18957218² = 718752228599048, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 96623 + ... + 96818.

Almost surely, 2^18957218 is an apocalyptic number.

18957218 is a deficient number, since it is larger than the sum of its proper divisors (14121364).

18957218 is a wasteful number, since it uses less digits than its factorization.

18957218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193457 (or 193450 counting only the distinct ones).

The product of its digits is 40320, while the sum is 41.

The square root of 18957218 is about 4353.9887459662. The cubic root of 18957218 is about 266.6397344328.

The spelling of 18957218 in words is "eighteen million, nine hundred fifty-seven thousand, two hundred eighteen".