205946779405 has 16 divisors (see below), whose sum is σ = 248517206784. Its totient is φ = 163839205440.

The previous prime is 205946779399. The next prime is 205946779427. The reversal of 205946779405 is 504977649502.

It is not a de Polignac number, because 205946779405 - 2¹³ = 205946771213 is a prime.

It is a super-4 number, since 4×205946779405⁴ (a number of 46 digits) contains 4444 as substring.

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 205946779405.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 505939 + ... + 817231.

It is an arithmetic number, because the mean of its divisors is an integer number (15532325424).

Almost surely, 2^205946779405 is an apocalyptic number.

It is an amenable number.

205946779405 is a deficient number, since it is larger than the sum of its proper divisors (42570427379).

205946779405 is a wasteful number, since it uses less digits than its factorization.

205946779405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312036.

The product of its (nonzero) digits is 19051200, while the sum is 58.

The spelling of 205946779405 in words is "two hundred five billion, nine hundred forty-six million, seven hundred seventy-nine thousand, four hundred five".