217280473 has 2 divisors, whose sum is σ = 217280474. Its totient is φ = 217280472.

The previous prime is 217280431. The next prime is 217280477. The reversal of 217280473 is 374082712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114318864 + 102961609 = 10692^2 + 10147^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217280473 is a prime.

It is not a weakly prime, because it can be changed into another prime (217280477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108640236 + 108640237.

It is an arithmetic number, because the mean of its divisors is an integer number (108640237).

Almost surely, 2^217280473 is an apocalyptic number.

It is an amenable number.

217280473 is a deficient number, since it is larger than the sum of its proper divisors (1).

217280473 is an equidigital number, since it uses as much as digits as its factorization.

217280473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 217280473 is about 14740.4366624602. The cubic root of 217280473 is about 601.1832879966.

The spelling of 217280473 in words is "two hundred seventeen million, two hundred eighty thousand, four hundred seventy-three".