205651 has 2 divisors, whose sum is σ = 205652. Its totient is φ = 205650.

The previous prime is 205633. The next prime is 205657. The reversal of 205651 is 156502.

It is a happy number.

205651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205651 - 2⁵ = 205619 is a prime.

It is not a weakly prime, because it can be changed into another prime (205657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102825 + 102826.

It is an arithmetic number, because the mean of its divisors is an integer number (102826).

2²⁰⁵⁶⁵¹ is an apocalyptic number.

205651 is a deficient number, since it is larger than the sum of its proper divisors (1).

205651 is an equidigital number, since it uses as much as digits as its factorization.

205651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 205651 is about 453.4875963023. The cubic root of 205651 is about 59.0260346654.

It can be divided in two parts, 20 and 5651, that added together give a triangular number (5671 = T₁₀₆).

The spelling of 205651 in words is "two hundred five thousand, six hundred fifty-one".