217122113 has 8 divisors (see below), whose sum is σ = 247578408. Its totient is φ = 188630784.

The previous prime is 217122089. The next prime is 217122127. The reversal of 217122113 is 311221712.

It can be written as a sum of positive squares in 4 ways, for example, as 9560464 + 207561649 = 3092^2 + 14407^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 217122113 - 2⁸ = 217121857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217122193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 491006 + ... + 491447.

It is an arithmetic number, because the mean of its divisors is an integer number (30947301).

Almost surely, 2^217122113 is an apocalyptic number.

It is an amenable number.

217122113 is a deficient number, since it is larger than the sum of its proper divisors (30456295).

217122113 is a wasteful number, since it uses less digits than its factorization.

217122113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982483.

The product of its digits is 168, while the sum is 20.

The square root of 217122113 is about 14735.0640650117. The cubic root of 217122113 is about 601.0371995140.

Adding to 217122113 its reverse (311221712), we get a palindrome (528343825).

The spelling of 217122113 in words is "two hundred seventeen million, one hundred twenty-two thousand, one hundred thirteen".