2185872817 has 2 divisors, whose sum is σ = 2185872818. Its totient is φ = 2185872816.

The previous prime is 2185872779. The next prime is 2185872823. The reversal of 2185872817 is 7182785812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1424609536 + 761263281 = 37744^2 + 27591^2 .

It is a cyclic number.

It is not a de Polignac number, because 2185872817 - 2¹⁵ = 2185840049 is a prime.

It is not a weakly prime, because it can be changed into another prime (2185872847) 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, 1092936408 + 1092936409.

It is an arithmetic number, because the mean of its divisors is an integer number (1092936409).

Almost surely, 2^2185872817 is an apocalyptic number.

It is an amenable number.

2185872817 is a deficient number, since it is larger than the sum of its proper divisors (1).

2185872817 is an equidigital number, since it uses as much as digits as its factorization.

2185872817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 501760, while the sum is 49.

The square root of 2185872817 is about 46753.3187805957. The cubic root of 2185872817 is about 1297.8015736923.

The spelling of 2185872817 in words is "two billion, one hundred eighty-five million, eight hundred seventy-two thousand, eight hundred seventeen".