217442047 has 2 divisors, whose sum is σ = 217442048. Its totient is φ = 217442046.

The previous prime is 217442033. The next prime is 217442051. The reversal of 217442047 is 740244712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 217442047 - 2¹⁵ = 217409279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217442077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108721023 + 108721024.

It is an arithmetic number, because the mean of its divisors is an integer number (108721024).

Almost surely, 2^217442047 is an apocalyptic number.

217442047 is a deficient number, since it is larger than the sum of its proper divisors (1).

217442047 is an equidigital number, since it uses as much as digits as its factorization.

217442047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12544, while the sum is 31.

The square root of 217442047 is about 14745.9162821440. The cubic root of 217442047 is about 601.3322682829.

Adding to 217442047 its reverse (740244712), we get a palindrome (957686759).

The spelling of 217442047 in words is "two hundred seventeen million, four hundred forty-two thousand, forty-seven".