205449138117 has 12 divisors (see below), whose sum is σ = 296859857580. Its totient is φ = 136919942208.

The previous prime is 205449138113. The next prime is 205449138137. The reversal of 205449138117 is 711831944502.

205449138117 is a `hidden beast` number, since 2 + 0 + 544 + 9 + 13 + 81 + 17 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 99902773476 + 105546364641 = 316074^2 + 324879^2 .

It is not a de Polignac number, because 205449138117 - 2² = 205449138113 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205449138113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3817618 + ... + 3871059.

It is an arithmetic number, because the mean of its divisors is an integer number (24738321465).

Almost surely, 2^205449138117 is an apocalyptic number.

It is an amenable number.

205449138117 is a deficient number, since it is larger than the sum of its proper divisors (91410719463).

205449138117 is a wasteful number, since it uses less digits than its factorization.

205449138117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7691652 (or 7691649 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 205449138117 in words is "two hundred five billion, four hundred forty-nine million, one hundred thirty-eight thousand, one hundred seventeen".