217475985 has 16 divisors (see below), whose sum is σ = 368430336. Its totient is φ = 109164288.

The previous prime is 217475977. The next prime is 217475987. The reversal of 217475985 is 589574712.

It is not a de Polignac number, because 217475985 - 2³ = 217475977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (217475987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 426169 + ... + 426678.

It is an arithmetic number, because the mean of its divisors is an integer number (23026896).

Almost surely, 2^217475985 is an apocalyptic number.

It is an amenable number.

217475985 is a deficient number, since it is larger than the sum of its proper divisors (150954351).

217475985 is a wasteful number, since it uses less digits than its factorization.

217475985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852872.

The product of its digits is 705600, while the sum is 48.

The square root of 217475985 is about 14747.0669965251. The cubic root of 217475985 is about 601.3635516419.

The spelling of 217475985 in words is "two hundred seventeen million, four hundred seventy-five thousand, nine hundred eighty-five".