205951 has 2 divisors, whose sum is σ = 205952. Its totient is φ = 205950.

The previous prime is 205949. The next prime is 205957. The reversal of 205951 is 159502.

205951 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205951 - 2¹ = 205949 is a prime.

Together with 205949, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102975 + 102976.

It is an arithmetic number, because the mean of its divisors is an integer number (102976).

2²⁰⁵⁹⁵¹ is an apocalyptic number.

205951 is a deficient number, since it is larger than the sum of its proper divisors (1).

205951 is an equidigital number, since it uses as much as digits as its factorization.

205951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 205951 is about 453.8182455565. The cubic root of 205951 is about 59.0547227612.

It can be divided in two parts, 205 and 951, that added together give a square (1156 = 34²).

The spelling of 205951 in words is "two hundred five thousand, nine hundred fifty-one".