679986217 has 2 divisors, whose sum is σ = 679986218. Its totient is φ = 679986216.

The previous prime is 679986173. The next prime is 679986227. The reversal of 679986217 is 712689976.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624200256 + 55785961 = 24984^2 + 7469^2 .

It is a cyclic number.

It is not a de Polignac number, because 679986217 - 2⁷ = 679986089 is a prime.

It is not a weakly prime, because it can be changed into another prime (679986227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339993108 + 339993109.

It is an arithmetic number, because the mean of its divisors is an integer number (339993109).

Almost surely, 2^679986217 is an apocalyptic number.

It is an amenable number.

679986217 is a deficient number, since it is larger than the sum of its proper divisors (1).

679986217 is an equidigital number, since it uses as much as digits as its factorization.

679986217 is an evil number, because the sum of its binary digits is even.

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

The square root of 679986217 is about 26076.5453425104. The cubic root of 679986217 is about 879.3599930676.

The spelling of 679986217 in words is "six hundred seventy-nine million, nine hundred eighty-six thousand, two hundred seventeen".