216678819 has 32 divisors (see below), whose sum is σ = 336559104. Its totient is φ = 121443840.

The previous prime is 216678799. The next prime is 216678827. The reversal of 216678819 is 918876612.

It is not a de Polignac number, because 216678819 - 2¹⁵ = 216646051 is a prime.

It is a super-2 number, since 2×216678819² = 93899421206469522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216674819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 430522 + ... + 431024.

It is an arithmetic number, because the mean of its divisors is an integer number (10517472).

Almost surely, 2^216678819 is an apocalyptic number.

216678819 is a deficient number, since it is larger than the sum of its proper divisors (119880285).

216678819 is a wasteful number, since it uses less digits than its factorization.

216678819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867.

The product of its digits is 290304, while the sum is 48.

The square root of 216678819 is about 14720.0142323301. The cubic root of 216678819 is about 600.6278788289.

The spelling of 216678819 in words is "two hundred sixteen million, six hundred seventy-eight thousand, eight hundred nineteen".