823993813 has 2 divisors, whose sum is σ = 823993814. Its totient is φ = 823993812.

The previous prime is 823993789. The next prime is 823993817. The reversal of 823993813 is 318399328.

823993813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 823575204 + 418609 = 28698^2 + 647^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-823993813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (823993817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411996906 + 411996907.

It is an arithmetic number, because the mean of its divisors is an integer number (411996907).

Almost surely, 2^823993813 is an apocalyptic number.

It is an amenable number.

823993813 is a deficient number, since it is larger than the sum of its proper divisors (1).

823993813 is an equidigital number, since it uses as much as digits as its factorization.

823993813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 46.

The square root of 823993813 is about 28705.2924214334. The cubic root of 823993813 is about 937.5072830960.

The spelling of 823993813 in words is "eight hundred twenty-three million, nine hundred ninety-three thousand, eight hundred thirteen".