205106189 has 4 divisors (see below), whose sum is σ = 205136256. Its totient is φ = 205076124.

The previous prime is 205106179. The next prime is 205106191. The reversal of 205106189 is 981601502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205106189 is a prime.

It is a super-2 number, since 2×205106189² = 84137097532207442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205106119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 662 + ... + 20264.

It is an arithmetic number, because the mean of its divisors is an integer number (51284064).

Almost surely, 2^205106189 is an apocalyptic number.

It is an amenable number.

205106189 is a deficient number, since it is larger than the sum of its proper divisors (30067).

205106189 is a wasteful number, since it uses less digits than its factorization.

205106189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30066.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 205106189 is about 14321.5288639167. The cubic root of 205106189 is about 589.7386460945.

The spelling of 205106189 in words is "two hundred five million, one hundred six thousand, one hundred eighty-nine".