217323643 has 2 divisors, whose sum is σ = 217323644. Its totient is φ = 217323642.

The previous prime is 217323641. The next prime is 217323683. The reversal of 217323643 is 346323712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 217323643 - 2¹ = 217323641 is a prime.

Together with 217323641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (217323641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108661821 + 108661822.

It is an arithmetic number, because the mean of its divisors is an integer number (108661822).

Almost surely, 2^217323643 is an apocalyptic number.

217323643 is a deficient number, since it is larger than the sum of its proper divisors (1).

217323643 is an equidigital number, since it uses as much as digits as its factorization.

217323643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 31.

The square root of 217323643 is about 14741.9009289847. The cubic root of 217323643 is about 601.2231003853.

The spelling of 217323643 in words is "two hundred seventeen million, three hundred twenty-three thousand, six hundred forty-three".