205106561047 has 4 divisors (see below), whose sum is σ = 205157221200. Its totient is φ = 205055900896.

The previous prime is 205106561039. The next prime is 205106561081. The reversal of 205106561047 is 740165601502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 205106561047 - 2³ = 205106561039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205106560997 and 205106561015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205106561017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25324003 + ... + 25332100.

It is an arithmetic number, because the mean of its divisors is an integer number (51289305300).

Almost surely, 2^205106561047 is an apocalyptic number.

205106561047 is a deficient number, since it is larger than the sum of its proper divisors (50660153).

205106561047 is an equidigital number, since it uses as much as digits as its factorization.

205106561047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50660152.

The product of its (nonzero) digits is 50400, while the sum is 37.

It can be divided in two parts, 2051065 and 61047, that added together give a palindrome (2112112).

The spelling of 205106561047 in words is "two hundred five billion, one hundred six million, five hundred sixty-one thousand, forty-seven".