216879823 has 2 divisors, whose sum is σ = 216879824. Its totient is φ = 216879822.

The previous prime is 216879809. The next prime is 216879841. The reversal of 216879823 is 328978612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216879823 is a prime.

It is a super-2 number, since 2×216879823² = 94073715249022658, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216879853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108439911 + 108439912.

It is an arithmetic number, because the mean of its divisors is an integer number (108439912).

Almost surely, 2^216879823 is an apocalyptic number.

216879823 is a deficient number, since it is larger than the sum of its proper divisors (1).

216879823 is an equidigital number, since it uses as much as digits as its factorization.

216879823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 46.

The square root of 216879823 is about 14726.8402245696. The cubic root of 216879823 is about 600.8135473286.

The spelling of 216879823 in words is "two hundred sixteen million, eight hundred seventy-nine thousand, eight hundred twenty-three".