217031113 has 4 divisors (see below), whose sum is σ = 233725828. Its totient is φ = 200336400.

The previous prime is 217031071. The next prime is 217031119. The reversal of 217031113 is 311130712.

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 96294969 + 120736144 = 9813^2 + 10988^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217031113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217031119) 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, 8347338 + ... + 8347363.

It is an arithmetic number, because the mean of its divisors is an integer number (58431457).

Almost surely, 2^217031113 is an apocalyptic number.

It is an amenable number.

217031113 is a deficient number, since it is larger than the sum of its proper divisors (16694715).

217031113 is a wasteful number, since it uses less digits than its factorization.

217031113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16694714.

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 217031113 is about 14731.9758688371. The cubic root of 217031113 is about 600.9532190796.

Adding to 217031113 its reverse (311130712), we get a palindrome (528161825).

The spelling of 217031113 in words is "two hundred seventeen million, thirty-one thousand, one hundred thirteen".