205750989791 has 4 divisors (see below), whose sum is σ = 209633083992. Its totient is φ = 201868895592.

The previous prime is 205750989767. The next prime is 205750989823. The reversal of 205750989791 is 197989057502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 197989057502 = 2 ⋅98994528751.

It is a cyclic number.

It is not a de Polignac number, because 205750989791 - 2³⁴ = 188571120607 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 (205750989701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1941047021 + ... + 1941047126.

It is an arithmetic number, because the mean of its divisors is an integer number (52408270998).

Almost surely, 2^205750989791 is an apocalyptic number.

205750989791 is a deficient number, since it is larger than the sum of its proper divisors (3882094201).

205750989791 is an equidigital number, since it uses as much as digits as its factorization.

205750989791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3882094200.

The product of its (nonzero) digits is 14288400, while the sum is 62.

The spelling of 205750989791 in words is "two hundred five billion, seven hundred fifty million, nine hundred eighty-nine thousand, seven hundred ninety-one".