217116853 has 4 divisors (see below), whose sum is σ = 222412428. Its totient is φ = 211821280.

The previous prime is 217116841. The next prime is 217116863. The reversal of 217116853 is 358611712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13712209 + 203404644 = 3703^2 + 14262^2 .

It is a cyclic number.

It is not a de Polignac number, because 217116853 - 2¹⁷ = 216985781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217116863) 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, 2647726 + ... + 2647807.

It is an arithmetic number, because the mean of its divisors is an integer number (55603107).

Almost surely, 2^217116853 is an apocalyptic number.

It is an amenable number.

217116853 is a deficient number, since it is larger than the sum of its proper divisors (5295575).

217116853 is an equidigital number, since it uses as much as digits as its factorization.

217116853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5295574.

The product of its digits is 10080, while the sum is 34.

The square root of 217116853 is about 14734.8855781102. The cubic root of 217116853 is about 601.0323458993.

The spelling of 217116853 in words is "two hundred seventeen million, one hundred sixteen thousand, eight hundred fifty-three".