205393781375999 has 4 divisors (see below), whose sum is σ = 206702022021864. Its totient is φ = 204085540730136.

The previous prime is 205393781375977. The next prime is 205393781376031. The reversal of 205393781375999 is 999573187393502.

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 205393781375999 - 2²⁸ = 205393512940543 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 (205393781377999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 654120322697 + ... + 654120323010.

It is an arithmetic number, because the mean of its divisors is an integer number (51675505505466).

Almost surely, 2^{205393781375999} is an apocalyptic number.

205393781375999 is a deficient number, since it is larger than the sum of its proper divisors (1308240645865).

205393781375999 is a wasteful number, since it uses less digits than its factorization.

205393781375999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1308240645864.

The product of its (nonzero) digits is 3472081200, while the sum is 80.

The spelling of 205393781375999 in words is "two hundred five trillion, three hundred ninety-three billion, seven hundred eighty-one million, three hundred seventy-five thousand, nine hundred ninety-nine".