205455643 has 2 divisors, whose sum is σ = 205455644. Its totient is φ = 205455642.

The previous prime is 205455637. The next prime is 205455661. The reversal of 205455643 is 346554502.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205455643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205455599 and 205455608.

It is not a weakly prime, because it can be changed into another prime (205455673) 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 as a sum of consecutive naturals, namely, 102727821 + 102727822.

It is an arithmetic number, because the mean of its divisors is an integer number (102727822).

Almost surely, 2^205455643 is an apocalyptic number.

205455643 is a deficient number, since it is larger than the sum of its proper divisors (1).

205455643 is an equidigital number, since it uses as much as digits as its factorization.

205455643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72000, while the sum is 34.

The square root of 205455643 is about 14333.7239752969. The cubic root of 205455643 is about 590.0733826182.

The spelling of 205455643 in words is "two hundred five million, four hundred fifty-five thousand, six hundred forty-three".