216906 has 8 divisors (see below), whose sum is σ = 433824. Its totient is φ = 72300.

The previous prime is 216901. The next prime is 216911. The reversal of 216906 is 609612.

It is an interprime number because it is at equal distance from previous prime (216901) and next prime (216911).

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

216906 is an admirable number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18070 + ... + 18081.

It is an arithmetic number, because the mean of its divisors is an integer number (54228).

2²¹⁶⁹⁰⁶ is an apocalyptic number.

216906 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216906 is a wasteful number, since it uses less digits than its factorization.

216906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36156.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 216906 is about 465.7316824095. The cubic root of 216906 is about 60.0837718723.

The spelling of 216906 in words is "two hundred sixteen thousand, nine hundred six".