820123749779 has 2 divisors, whose sum is σ = 820123749780. Its totient is φ = 820123749778.

The previous prime is 820123749773. The next prime is 820123749793. The reversal of 820123749779 is 977947321028.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 820123749779 - 2⁴ = 820123749763 is a prime.

It is not a weakly prime, because it can be changed into another prime (820123749773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410061874889 + 410061874890.

It is an arithmetic number, because the mean of its divisors is an integer number (410061874890).

Almost surely, 2^820123749779 is an apocalyptic number.

820123749779 is a deficient number, since it is larger than the sum of its proper divisors (1).

820123749779 is an equidigital number, since it uses as much as digits as its factorization.

820123749779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10668672, while the sum is 59.

The spelling of 820123749779 in words is "eight hundred twenty billion, one hundred twenty-three million, seven hundred forty-nine thousand, seven hundred seventy-nine".