197812817 has 2 divisors, whose sum is σ = 197812818. Its totient is φ = 197812816.

The previous prime is 197812807. The next prime is 197812831. The reversal of 197812817 is 718218791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179801281 + 18011536 = 13409^2 + 4244^2 .

It is a cyclic number.

It is not a de Polignac number, because 197812817 - 2¹⁸ = 197550673 is a prime.

It is not a weakly prime, because it can be changed into another prime (197812807) 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, 98906408 + 98906409.

It is an arithmetic number, because the mean of its divisors is an integer number (98906409).

Almost surely, 2^197812817 is an apocalyptic number.

It is an amenable number.

197812817 is a deficient number, since it is larger than the sum of its proper divisors (1).

197812817 is an equidigital number, since it uses as much as digits as its factorization.

197812817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 44.

The square root of 197812817 is about 14064.5944484724. The cubic root of 197812817 is about 582.6639417716.

The spelling of 197812817 in words is "one hundred ninety-seven million, eight hundred twelve thousand, eight hundred seventeen".