997877813 has 2 divisors, whose sum is σ = 997877814. Its totient is φ = 997877812.

The previous prime is 997877809. The next prime is 997877843. The reversal of 997877813 is 318778799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 997106929 + 770884 = 31577^2 + 878^2 .

It is an emirp because it is prime and its reverse (318778799) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 997877813 - 2² = 997877809 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997877843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498938906 + 498938907.

It is an arithmetic number, because the mean of its divisors is an integer number (498938907).

Almost surely, 2^997877813 is an apocalyptic number.

It is an amenable number.

997877813 is a deficient number, since it is larger than the sum of its proper divisors (1).

997877813 is an equidigital number, since it uses as much as digits as its factorization.

997877813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5334336, while the sum is 59.

The square root of 997877813 is about 31589.2040577157. The cubic root of 997877813 is about 999.2921033339.

The spelling of 997877813 in words is "nine hundred ninety-seven million, eight hundred seventy-seven thousand, eight hundred thirteen".