217923 has 8 divisors (see below), whose sum is σ = 307728. Its totient is φ = 136704.

The previous prime is 217909. The next prime is 217933. The reversal of 217923 is 329712.

217923 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 217923 - 2⁴ = 217907 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 217893 and 217902.

It is not an unprimeable number, because it can be changed into a prime (217933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2086 + ... + 2187.

It is an arithmetic number, because the mean of its divisors is an integer number (38466).

2²¹⁷⁹²³ is an apocalyptic number.

217923 is a deficient number, since it is larger than the sum of its proper divisors (89805).

217923 is a wasteful number, since it uses less digits than its factorization.

217923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4293.

The product of its digits is 756, while the sum is 24.

The square root of 217923 is about 466.8222359743. The cubic root of 217923 is about 60.1775297572.

The spelling of 217923 in words is "two hundred seventeen thousand, nine hundred twenty-three".