217287131 has 2 divisors, whose sum is σ = 217287132. Its totient is φ = 217287130.

The previous prime is 217287113. The next prime is 217287137. The reversal of 217287131 is 131782712.

Together with previous prime (217287113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 217287131 - 2¹⁰ = 217286107 is a prime.

It is a super-2 number, since 2×217287131² = 94427394596422322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (217287137) by changing a digit.

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, 108643565 + 108643566.

It is an arithmetic number, because the mean of its divisors is an integer number (108643566).

Almost surely, 2^217287131 is an apocalyptic number.

217287131 is a deficient number, since it is larger than the sum of its proper divisors (1).

217287131 is an equidigital number, since it uses as much as digits as its factorization.

217287131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4704, while the sum is 32.

The square root of 217287131 is about 14740.6625020723. The cubic root of 217287131 is about 601.1894285046.

The spelling of 217287131 in words is "two hundred seventeen million, two hundred eighty-seven thousand, one hundred thirty-one".