217124985 has 32 divisors (see below), whose sum is σ = 433124352. Its totient is φ = 90233280.

The previous prime is 217124983. The next prime is 217124987. The reversal of 217124985 is 589421712.

It is an interprime number because it is at equal distance from previous prime (217124983) and next prime (217124987).

It is not a de Polignac number, because 217124985 - 2¹ = 217124983 is a prime.

It is a super-2 number, since 2×217124985² = 94286518222500450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (217124983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92839 + ... + 95148.

It is an arithmetic number, because the mean of its divisors is an integer number (13535136).

Almost surely, 2^217124985 is an apocalyptic number.

It is an amenable number.

217124985 is a deficient number, since it is larger than the sum of its proper divisors (215999367).

217124985 is a wasteful number, since it uses less digits than its factorization.

217124985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188013.

The product of its digits is 40320, while the sum is 39.

The square root of 217124985 is about 14735.1615193048. The cubic root of 217124985 is about 601.0398495914.

The spelling of 217124985 in words is "two hundred seventeen million, one hundred twenty-four thousand, nine hundred eighty-five".