217090 has 16 divisors (see below), whose sum is σ = 414072. Its totient is φ = 81664.

The previous prime is 217081. The next prime is 217111. The reversal of 217090 is 90712.

It can be written as a sum of positive squares in 4 ways, for example, as 205209 + 11881 = 453^2 + 109^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 469 + ... + 808.

2²¹⁷⁰⁹⁰ is an apocalyptic number.

217090 is a deficient number, since it is larger than the sum of its proper divisors (196982).

217090 is a wasteful number, since it uses less digits than its factorization.

217090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1301.

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 217090 is about 465.9291791678. The cubic root of 217090 is about 60.1007566329.

The spelling of 217090 in words is "two hundred seventeen thousand, ninety".