1817995897 has 2 divisors, whose sum is σ = 1817995898. Its totient is φ = 1817995896.

The previous prime is 1817995853. The next prime is 1817995903. The reversal of 1817995897 is 7985997181.

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., 1130035456 + 687960441 = 33616^2 + 26229^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1817995897 is a prime.

It is not a weakly prime, because it can be changed into another prime (1817995847) 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, 908997948 + 908997949.

It is an arithmetic number, because the mean of its divisors is an integer number (908997949).

Almost surely, 2^1817995897 is an apocalyptic number.

It is an amenable number.

1817995897 is a deficient number, since it is larger than the sum of its proper divisors (1).

1817995897 is an equidigital number, since it uses as much as digits as its factorization.

1817995897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11430720, while the sum is 64.

The square root of 1817995897 is about 42637.9630962831. The cubic root of 1817995897 is about 1220.4808408734.

The spelling of 1817995897 in words is "one billion, eight hundred seventeen million, nine hundred ninety-five thousand, eight hundred ninety-seven".