997813 has 2 divisors, whose sum is σ = 997814. Its totient is φ = 997812.

The previous prime is 997811. The next prime is 997877. The reversal of 997813 is 318799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 964324 + 33489 = 982^2 + 183^2 .

It is a cyclic number.

It is not a de Polignac number, because 997813 - 2¹ = 997811 is a prime.

Together with 997811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498906 + 498907.

It is an arithmetic number, because the mean of its divisors is an integer number (498907).

2⁹⁹⁷⁸¹³ is an apocalyptic number.

It is an amenable number.

997813 is a deficient number, since it is larger than the sum of its proper divisors (1).

997813 is an equidigital number, since it uses as much as digits as its factorization.

997813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 37.

The square root of 997813 is about 998.9059014742. The cubic root of 997813 is about 99.9270467912.

The spelling of 997813 in words is "nine hundred ninety-seven thousand, eight hundred thirteen".