205381007663 has 4 divisors (see below), whose sum is σ = 221179546728. Its totient is φ = 189582468600.

The previous prime is 205381007659. The next prime is 205381007717. The reversal of 205381007663 is 366700183502.

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 205381007663 - 2² = 205381007659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205381007663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205381007063) 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 3 ways as a sum of consecutive naturals, for example, 7899269513 + ... + 7899269538.

It is an arithmetic number, because the mean of its divisors is an integer number (55294886682).

Almost surely, 2^205381007663 is an apocalyptic number.

205381007663 is a deficient number, since it is larger than the sum of its proper divisors (15798539065).

205381007663 is a wasteful number, since it uses less digits than its factorization.

205381007663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15798539064.

The product of its (nonzero) digits is 181440, while the sum is 41.

It can be divided in two parts, 20538 and 1007663, that added together give a palindrome (1028201).

The spelling of 205381007663 in words is "two hundred five billion, three hundred eighty-one million, seven thousand, six hundred sixty-three".