679285556821 has 2 divisors, whose sum is σ = 679285556822. Its totient is φ = 679285556820.

The previous prime is 679285556801. The next prime is 679285556891. The reversal of 679285556821 is 128655582976.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 568193333796 + 111092223025 = 753786^2 + 333305^2 .

It is a cyclic number.

It is not a de Polignac number, because 679285556821 - 2⁷ = 679285556693 is a prime.

It is a super-2 number, since 2×679285556821² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (679285556801) 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, 339642778410 + 339642778411.

It is an arithmetic number, because the mean of its divisors is an integer number (339642778411).

Almost surely, 2^679285556821 is an apocalyptic number.

It is an amenable number.

679285556821 is a deficient number, since it is larger than the sum of its proper divisors (1).

679285556821 is an equidigital number, since it uses as much as digits as its factorization.

679285556821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576000, while the sum is 64.

The spelling of 679285556821 in words is "six hundred seventy-nine billion, two hundred eighty-five million, five hundred fifty-six thousand, eight hundred twenty-one".