205605686879 has 6 divisors (see below), whose sum is σ = 216996584040. Its totient is φ = 194784334596.

The previous prime is 205605686857. The next prime is 205605686887. The reversal of 205605686879 is 978686506502.

It is not a de Polignac number, because 205605686879 - 2⁸ = 205605686623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205602686879) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 284772059 + ... + 284772780.

It is an arithmetic number, because the mean of its divisors is an integer number (36166097340).

Almost surely, 2^205605686879 is an apocalyptic number.

205605686879 is a deficient number, since it is larger than the sum of its proper divisors (11390897161).

205605686879 is an equidigital number, since it uses as much as digits as its factorization.

205605686879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569544877 (or 569544858 counting only the distinct ones).

The product of its (nonzero) digits is 43545600, while the sum is 62.

The spelling of 205605686879 in words is "two hundred five billion, six hundred five million, six hundred eighty-six thousand, eight hundred seventy-nine".