217242873 has 12 divisors (see below), whose sum is σ = 322276708. Its totient is φ = 140914080.

The previous prime is 217242863. The next prime is 217242917. The reversal of 217242873 is 378242712.

It can be written as a sum of positive squares in 2 ways, for example, as 204261264 + 12981609 = 14292^2 + 3603^2 .

It is not a de Polignac number, because 217242873 - 2¹³ = 217234681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217242803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 325858 + ... + 326523.

Almost surely, 2^217242873 is an apocalyptic number.

It is an amenable number.

217242873 is a deficient number, since it is larger than the sum of its proper divisors (105033835).

217242873 is a wasteful number, since it uses less digits than its factorization.

217242873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652424 (or 652421 counting only the distinct ones).

The product of its digits is 37632, while the sum is 36.

The square root of 217242873 is about 14739.1612040849. The cubic root of 217242873 is about 601.1486080960.

The spelling of 217242873 in words is "two hundred seventeen million, two hundred forty-two thousand, eight hundred seventy-three".