216923 has 12 divisors (see below), whose sum is σ = 266760. Its totient is φ = 175392.

The previous prime is 216919. The next prime is 216947. The reversal of 216923 is 329612.

Added to its reverse (329612) it gives a triangular number (546535 = T₁₀₄₅).

It is not a de Polignac number, because 216923 - 2² = 216919 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (216973) 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, 815 + ... + 1047.

It is an arithmetic number, because the mean of its divisors is an integer number (22230).

2²¹⁶⁹²³ is an apocalyptic number.

216923 is a deficient number, since it is larger than the sum of its proper divisors (49837).

216923 is a wasteful number, since it uses less digits than its factorization.

216923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266 (or 259 counting only the distinct ones).

The product of its digits is 648, while the sum is 23.

The square root of 216923 is about 465.7499329039. The cubic root of 216923 is about 60.0853415192.

Adding to 216923 its reverse (329612), we get a triangular number (546535 = T₁₀₄₅).

The spelling of 216923 in words is "two hundred sixteen thousand, nine hundred twenty-three".