205180517705 has 4 divisors (see below), whose sum is σ = 246216621252. Its totient is φ = 164144414160.

The previous prime is 205180517681. The next prime is 205180517753. The reversal of 205180517705 is 507715081502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 507715081502 = 2 ⋅253857540751.

It can be written as a sum of positive squares in 2 ways, for example, as 161831612089 + 43348905616 = 402283^2 + 208204^2 .

It is a de Polignac number, because none of the positive numbers 2^k-205180517705 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20518051766 + ... + 20518051775.

It is an arithmetic number, because the mean of its divisors is an integer number (61554155313).

Almost surely, 2^205180517705 is an apocalyptic number.

It is an amenable number.

205180517705 is a deficient number, since it is larger than the sum of its proper divisors (41036103547).

205180517705 is an equidigital number, since it uses as much as digits as its factorization.

205180517705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41036103546.

The product of its (nonzero) digits is 98000, while the sum is 41.

The spelling of 205180517705 in words is "two hundred five billion, one hundred eighty million, five hundred seventeen thousand, seven hundred five".