18947217 has 8 divisors (see below), whose sum is σ = 25306624. Its totient is φ = 12609648.

The previous prime is 18947213. The next prime is 18947311. The reversal of 18947217 is 71274981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18947217 - 2² = 18947213 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18947213) 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, 3313 + ... + 6990.

It is an arithmetic number, because the mean of its divisors is an integer number (3163328).

Almost surely, 2^18947217 is an apocalyptic number.

It is an amenable number.

18947217 is a deficient number, since it is larger than the sum of its proper divisors (6359407).

18947217 is a wasteful number, since it uses less digits than its factorization.

18947217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10919.

The product of its digits is 28224, while the sum is 39.

The square root of 18947217 is about 4352.8401073322. The cubic root of 18947217 is about 266.5928370266.

The spelling of 18947217 in words is "eighteen million, nine hundred forty-seven thousand, two hundred seventeen".