205897819 has 2 divisors, whose sum is σ = 205897820. Its totient is φ = 205897818.

The previous prime is 205897801. The next prime is 205897823. The reversal of 205897819 is 918798502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205897819 - 2¹¹ = 205895771 is a prime.

It is a super-4 number, since 4×205897819⁴ (a number of 34 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (205897619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102948909 + 102948910.

It is an arithmetic number, because the mean of its divisors is an integer number (102948910).

Almost surely, 2^205897819 is an apocalyptic number.

205897819 is a deficient number, since it is larger than the sum of its proper divisors (1).

205897819 is an equidigital number, since it uses as much as digits as its factorization.

205897819 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 49.

The square root of 205897819 is about 14349.1400090737. The cubic root of 205897819 is about 590.4963925499.

The spelling of 205897819 in words is "two hundred five million, eight hundred ninety-seven thousand, eight hundred nineteen".