216978679 has 2 divisors, whose sum is σ = 216978680. Its totient is φ = 216978678.

The previous prime is 216978653. The next prime is 216978691. The reversal of 216978679 is 976879612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216978679 - 2¹³ = 216970487 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216978079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108489339 + 108489340.

It is an arithmetic number, because the mean of its divisors is an integer number (108489340).

Almost surely, 2^216978679 is an apocalyptic number.

216978679 is a deficient number, since it is larger than the sum of its proper divisors (1).

216978679 is an equidigital number, since it uses as much as digits as its factorization.

216978679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2286144, while the sum is 55.

The square root of 216978679 is about 14730.1961629844. The cubic root of 216978679 is about 600.9048190774.

The spelling of 216978679 in words is "two hundred sixteen million, nine hundred seventy-eight thousand, six hundred seventy-nine".