18143217 has 8 divisors (see below), whose sum is σ = 26878880. Its totient is φ = 12095460.

The previous prime is 18143173. The next prime is 18143227. The reversal of 18143217 is 71234181.

It is not a de Polignac number, because 18143217 - 2⁷ = 18143089 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 671971 = 18143217 / (1 + 8 + 1 + 4 + 3 + 2 + 1 + 7).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18143227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 335959 + ... + 336012.

It is an arithmetic number, because the mean of its divisors is an integer number (3359860).

Almost surely, 2^18143217 is an apocalyptic number.

It is an amenable number.

18143217 is a deficient number, since it is larger than the sum of its proper divisors (8735663).

18143217 is an equidigital number, since it uses as much as digits as its factorization.

18143217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671980 (or 671974 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 18143217 is about 4259.4855323149. The cubic root of 18143217 is about 262.7673683968.

Adding to 18143217 its reverse (71234181), we get a palindrome (89377398).

The spelling of 18143217 in words is "eighteen million, one hundred forty-three thousand, two hundred seventeen".