217973 has 4 divisors (see below), whose sum is σ = 249120. Its totient is φ = 186828.

The previous prime is 217969. The next prime is 217979. The reversal of 217973 is 379712.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 217973 - 2² = 217969 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15563 + ... + 15576.

It is an arithmetic number, because the mean of its divisors is an integer number (62280).

2²¹⁷⁹⁷³ is an apocalyptic number.

It is an amenable number.

217973 is a deficient number, since it is larger than the sum of its proper divisors (31147).

217973 is an equidigital number, since it uses as much as digits as its factorization.

217973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31146.

The product of its digits is 2646, while the sum is 29.

The square root of 217973 is about 466.8757864786. The cubic root of 217973 is about 60.1821317595.

The spelling of 217973 in words is "two hundred seventeen thousand, nine hundred seventy-three".