217115387 has 2 divisors, whose sum is σ = 217115388. Its totient is φ = 217115386.

The previous prime is 217115369. The next prime is 217115389. The reversal of 217115387 is 783511712.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 217115387 - 2⁶ = 217115323 is a prime.

Together with 217115389, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (217115389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108557693 + 108557694.

It is an arithmetic number, because the mean of its divisors is an integer number (108557694).

Almost surely, 2^217115387 is an apocalyptic number.

217115387 is a deficient number, since it is larger than the sum of its proper divisors (1).

217115387 is an equidigital number, since it uses as much as digits as its factorization.

217115387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11760, while the sum is 35.

The square root of 217115387 is about 14734.8358321360. The cubic root of 217115387 is about 601.0309931479.

The spelling of 217115387 in words is "two hundred seventeen million, one hundred fifteen thousand, three hundred eighty-seven".