216979 has 8 divisors (see below), whose sum is σ = 250880. Its totient is φ = 183816.

The previous prime is 216973. The next prime is 216991. The reversal of 216979 is 979612.

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

It is a cyclic number.

It is not a de Polignac number, because 216979 - 2⁵ = 216947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216973) 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 7 ways as a sum of consecutive naturals, for example, 862 + ... + 1084.

It is an arithmetic number, because the mean of its divisors is an integer number (31360).

2²¹⁶⁹⁷⁹ is an apocalyptic number.

216979 is a deficient number, since it is larger than the sum of its proper divisors (33901).

216979 is a wasteful number, since it uses less digits than its factorization.

216979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369.

The product of its digits is 6804, while the sum is 34.

The square root of 216979 is about 465.8100471222. The cubic root of 216979 is about 60.0905115405.

The spelling of 216979 in words is "two hundred sixteen thousand, nine hundred seventy-nine".