205400191 has 2 divisors, whose sum is σ = 205400192. Its totient is φ = 205400190.

The previous prime is 205400179. The next prime is 205400233. The reversal of 205400191 is 191004502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205400191 - 2⁵ = 205400159 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205400291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102700095 + 102700096.

It is an arithmetic number, because the mean of its divisors is an integer number (102700096).

Almost surely, 2^205400191 is an apocalyptic number.

205400191 is a deficient number, since it is larger than the sum of its proper divisors (1).

205400191 is an equidigital number, since it uses as much as digits as its factorization.

205400191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 205400191 is about 14331.7895253873. The cubic root of 205400191 is about 590.0202913638.

Adding to 205400191 its reverse (191004502), we get a palindrome (396404693).

The spelling of 205400191 in words is "two hundred five million, four hundred thousand, one hundred ninety-one".