217872868 has 6 divisors (see below), whose sum is σ = 381277526. Its totient is φ = 108936432.

The previous prime is 217872847. The next prime is 217872883. The reversal of 217872868 is 868278712.

It can be written as a sum of positive squares in only one way, i.e., 126517504 + 91355364 = 11248^2 + 9558^2 .

It is a super-2 number, since 2×217872868² = 94937173221090848, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27234105 + ... + 27234112.

Almost surely, 2^217872868 is an apocalyptic number.

It is an amenable number.

217872868 is a deficient number, since it is larger than the sum of its proper divisors (163404658).

217872868 is a wasteful number, since it uses less digits than its factorization.

217872868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54468221 (or 54468219 counting only the distinct ones).

The product of its digits is 602112, while the sum is 49.

The square root of 217872868 is about 14760.5171996106. The cubic root of 217872868 is about 601.7291489895.

The spelling of 217872868 in words is "two hundred seventeen million, eight hundred seventy-two thousand, eight hundred sixty-eight".