18805217 has 6 divisors (see below), whose sum is σ = 19216098. Its totient is φ = 18402944.

The previous prime is 18805211. The next prime is 18805223. The reversal of 18805217 is 71250881.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18805211) and next prime (18805223).

It can be written as a sum of positive squares in only one way, i.e., 18696976 + 108241 = 4324^2 + 329^2 .

It is not a de Polignac number, because 18805217 - 2⁴ = 18805201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18805211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2048 + ... + 6465.

It is an arithmetic number, because the mean of its divisors is an integer number (3202683).

Almost surely, 2^18805217 is an apocalyptic number.

It is an amenable number.

18805217 is a deficient number, since it is larger than the sum of its proper divisors (410881).

18805217 is an frugal number, since it uses more digits than its factorization.

18805217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8607 (or 8560 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 18805217 is about 4336.4982416692. The cubic root of 18805217 is about 265.9251725757.

The spelling of 18805217 in words is "eighteen million, eight hundred five thousand, two hundred seventeen".