820123749793 has 2 divisors, whose sum is σ = 820123749794. Its totient is φ = 820123749792.

The previous prime is 820123749779. The next prime is 820123749803. The reversal of 820123749793 is 397947321028.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 789588633744 + 30535116049 = 888588^2 + 174743^2 .

It is a cyclic number.

It is not a de Polignac number, because 820123749793 - 2⁹ = 820123749281 is a prime.

It is not a weakly prime, because it can be changed into another prime (820123749703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410061874896 + 410061874897.

It is an arithmetic number, because the mean of its divisors is an integer number (410061874897).

Almost surely, 2^820123749793 is an apocalyptic number.

It is an amenable number.

820123749793 is a deficient number, since it is larger than the sum of its proper divisors (1).

820123749793 is an equidigital number, since it uses as much as digits as its factorization.

820123749793 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4572288, while the sum is 55.

The spelling of 820123749793 in words is "eight hundred twenty billion, one hundred twenty-three million, seven hundred forty-nine thousand, seven hundred ninety-three".