18845217 has 20 divisors (see below), whose sum is σ = 28318356. Its totient is φ = 12489120.

The previous prime is 18845201. The next prime is 18845221. The reversal of 18845217 is 71254881.

It can be written as a sum of positive squares in 2 ways, for example, as 17969121 + 876096 = 4239^2 + 936^2 .

It is not a de Polignac number, because 18845217 - 2⁴ = 18845201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18845227) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15367 + ... + 16547.

Almost surely, 2^18845217 is an apocalyptic number.

It is an amenable number.

18845217 is a deficient number, since it is larger than the sum of its proper divisors (9473139).

18845217 is a wasteful number, since it uses less digits than its factorization.

18845217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1390 (or 1381 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 18845217 is about 4341.1078079218. The cubic root of 18845217 is about 266.1135861406.

The spelling of 18845217 in words is "eighteen million, eight hundred forty-five thousand, two hundred seventeen".