997860817 has 2 divisors, whose sum is σ = 997860818. Its totient is φ = 997860816.

The previous prime is 997860761. The next prime is 997860821. The reversal of 997860817 is 718068799.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 802532241 + 195328576 = 28329^2 + 13976^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997860817 is a prime.

It is not a weakly prime, because it can be changed into another prime (997860887) 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, 498930408 + 498930409.

It is an arithmetic number, because the mean of its divisors is an integer number (498930409).

Almost surely, 2^997860817 is an apocalyptic number.

It is an amenable number.

997860817 is a deficient number, since it is larger than the sum of its proper divisors (1).

997860817 is an equidigital number, since it uses as much as digits as its factorization.

997860817 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1524096, while the sum is 55.

The square root of 997860817 is about 31588.9350406119. The cubic root of 997860817 is about 999.2864299389.

The spelling of 997860817 in words is "nine hundred ninety-seven million, eight hundred sixty thousand, eight hundred seventeen".