217530539 has 2 divisors, whose sum is σ = 217530540. Its totient is φ = 217530538.

The previous prime is 217530491. The next prime is 217530559. The reversal of 217530539 is 935035712.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217530539 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 217530499 and 217530508.

It is not a weakly prime, because it can be changed into another prime (217530559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108765269 + 108765270.

It is an arithmetic number, because the mean of its divisors is an integer number (108765270).

Almost surely, 2^217530539 is an apocalyptic number.

217530539 is a deficient number, since it is larger than the sum of its proper divisors (1).

217530539 is an equidigital number, since it uses as much as digits as its factorization.

217530539 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28350, while the sum is 35.

The square root of 217530539 is about 14748.9165364782. The cubic root of 217530539 is about 601.4138315910.

The spelling of 217530539 in words is "two hundred seventeen million, five hundred thirty thousand, five hundred thirty-nine".