217320479 has 2 divisors, whose sum is σ = 217320480. Its totient is φ = 217320478.

The previous prime is 217320473. The next prime is 217320487. The reversal of 217320479 is 974023712.

217320479 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217320479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217320473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108660239 + 108660240.

It is an arithmetic number, because the mean of its divisors is an integer number (108660240).

Almost surely, 2^217320479 is an apocalyptic number.

217320479 is a deficient number, since it is larger than the sum of its proper divisors (1).

217320479 is an equidigital number, since it uses as much as digits as its factorization.

217320479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 217320479 is about 14741.7936154323. The cubic root of 217320479 is about 601.2201826491.

The spelling of 217320479 in words is "two hundred seventeen million, three hundred twenty thousand, four hundred seventy-nine".