205131491 has 2 divisors, whose sum is σ = 205131492. Its totient is φ = 205131490.

The previous prime is 205131473. The next prime is 205131541. The reversal of 205131491 is 194131502.

205131491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205131491 - 2⁶ = 205131427 is a prime.

It is equal to p_11347262 and since 205131491 and 11347262 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205131491.

It is not a weakly prime, because it can be changed into another prime (205131191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102565745 + 102565746.

It is an arithmetic number, because the mean of its divisors is an integer number (102565746).

Almost surely, 2^205131491 is an apocalyptic number.

205131491 is a deficient number, since it is larger than the sum of its proper divisors (1).

205131491 is an equidigital number, since it uses as much as digits as its factorization.

205131491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 205131491 is about 14322.4121920855. The cubic root of 205131491 is about 589.7628952469.

Adding to 205131491 its reverse (194131502), we get a palindrome (399262993).

The spelling of 205131491 in words is "two hundred five million, one hundred thirty-one thousand, four hundred ninety-one".