2100818387809 has 2 divisors, whose sum is σ = 2100818387810. Its totient is φ = 2100818387808.

The previous prime is 2100818387803. The next prime is 2100818387813. The reversal of 2100818387809 is 9087838180012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2022519155409 + 78299232400 = 1422153^2 + 279820^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100818387809 - 2⁵ = 2100818387777 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2100818387809.

It is not a weakly prime, because it can be changed into another prime (2100818387803) 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, 1050409193904 + 1050409193905.

It is an arithmetic number, because the mean of its divisors is an integer number (1050409193905).

Almost surely, 2^{2100818387809} is an apocalyptic number.

It is an amenable number.

2100818387809 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100818387809 is an equidigital number, since it uses as much as digits as its factorization.

2100818387809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1548288, while the sum is 55.

The spelling of 2100818387809 in words is "two trillion, one hundred billion, eight hundred eighteen million, three hundred eighty-seven thousand, eight hundred nine".