823989317 has 2 divisors, whose sum is σ = 823989318. Its totient is φ = 823989316.

The previous prime is 823989311. The next prime is 823989319. The reversal of 823989317 is 713989328.

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., 678810916 + 145178401 = 26054^2 + 12049^2 .

It is a cyclic number.

It is not a de Polignac number, because 823989317 - 2⁴ = 823989301 is a prime.

Together with 823989319, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (823989311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411994658 + 411994659.

It is an arithmetic number, because the mean of its divisors is an integer number (411994659).

Almost surely, 2^823989317 is an apocalyptic number.

It is an amenable number.

823989317 is a deficient number, since it is larger than the sum of its proper divisors (1).

823989317 is an equidigital number, since it uses as much as digits as its factorization.

823989317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 50.

The square root of 823989317 is about 28705.2141082417. The cubic root of 823989317 is about 937.5055779698.

The spelling of 823989317 in words is "eight hundred twenty-three million, nine hundred eighty-nine thousand, three hundred seventeen".