218028217 has 4 divisors (see below), whose sum is σ = 237848976. Its totient is φ = 198207460.

The previous prime is 218028203. The next prime is 218028241. The reversal of 218028217 is 712820812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 218028217 - 2¹¹ = 218026169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218028257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9910363 + ... + 9910384.

It is an arithmetic number, because the mean of its divisors is an integer number (59462244).

Almost surely, 2^218028217 is an apocalyptic number.

It is an amenable number.

218028217 is a deficient number, since it is larger than the sum of its proper divisors (19820759).

218028217 is a wasteful number, since it uses less digits than its factorization.

218028217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19820758.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 218028217 is about 14765.7785775082. The cubic root of 218028217 is about 601.8721311696.

The spelling of 218028217 in words is "two hundred eighteen million, twenty-eight thousand, two hundred seventeen".