204978218849 has 2 divisors, whose sum is σ = 204978218850. Its totient is φ = 204978218848.

The previous prime is 204978218827. The next prime is 204978218891. The reversal of 204978218849 is 948812879402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185257072225 + 19721146624 = 430415^2 + 140432^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204978218849 is a prime.

It is a super-3 number, since 3×204978218849³ (a number of 35 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 204978218791 and 204978218800.

It is not a weakly prime, because it can be changed into another prime (204978218449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102489109424 + 102489109425.

It is an arithmetic number, because the mean of its divisors is an integer number (102489109425).

Almost surely, 2^204978218849 is an apocalyptic number.

It is an amenable number.

204978218849 is a deficient number, since it is larger than the sum of its proper divisors (1).

204978218849 is an equidigital number, since it uses as much as digits as its factorization.

204978218849 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18579456, while the sum is 62.

The spelling of 204978218849 in words is "two hundred four billion, nine hundred seventy-eight million, two hundred eighteen thousand, eight hundred forty-nine".