205942191 has 16 divisors (see below), whose sum is σ = 337956864. Its totient is φ = 108628704.

The previous prime is 205942183. The next prime is 205942211. The reversal of 205942191 is 191249502.

It is not a de Polignac number, because 205942191 - 2³ = 205942183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205942171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 376911 + ... + 377456.

It is an arithmetic number, because the mean of its divisors is an integer number (21122304).

Almost surely, 2^205942191 is an apocalyptic number.

205942191 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

205942191 is a deficient number, since it is larger than the sum of its proper divisors (132014673).

205942191 is a wasteful number, since it uses less digits than its factorization.

205942191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 754390.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 205942191 is about 14350.6860811600. The cubic root of 205942191 is about 590.5388078024.

The spelling of 205942191 in words is "two hundred five million, nine hundred forty-two thousand, one hundred ninety-one".