205630403 has 4 divisors (see below), whose sum is σ = 224324088. Its totient is φ = 186936720.

The previous prime is 205630363. The next prime is 205630417. The reversal of 205630403 is 304036502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205630403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205630003) 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 in 3 ways as a sum of consecutive naturals, for example, 9346826 + ... + 9346847.

It is an arithmetic number, because the mean of its divisors is an integer number (56081022).

Almost surely, 2^205630403 is an apocalyptic number.

205630403 is a deficient number, since it is larger than the sum of its proper divisors (18693685).

205630403 is a wasteful number, since it uses less digits than its factorization.

205630403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18693684.

The product of its (nonzero) digits is 2160, while the sum is 23.

The square root of 205630403 is about 14339.8187924395. The cubic root of 205630403 is about 590.2406401317.

Adding to 205630403 its reverse (304036502), we get a palindrome (509666905).

The spelling of 205630403 in words is "two hundred five million, six hundred thirty thousand, four hundred three".