205081819 has 2 divisors, whose sum is σ = 205081820. Its totient is φ = 205081818.

The previous prime is 205081783. The next prime is 205081847. The reversal of 205081819 is 918180502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205081819 - 2⁷ = 205081691 is a prime.

It is a super-3 number, since 3×205081819³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (205081859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102540909 + 102540910.

It is an arithmetic number, because the mean of its divisors is an integer number (102540910).

Almost surely, 2^205081819 is an apocalyptic number.

205081819 is a deficient number, since it is larger than the sum of its proper divisors (1).

205081819 is an equidigital number, since it uses as much as digits as its factorization.

205081819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 205081819 is about 14320.6780216581. The cubic root of 205081819 is about 589.7152882749.

The spelling of 205081819 in words is "two hundred five million, eighty-one thousand, eight hundred nineteen".