205305405 has 16 divisors (see below), whose sum is σ = 339085824. Its totient is φ = 105963840.

The previous prime is 205305403. The next prime is 205305407. The reversal of 205305405 is 504503502.

It is an interprime number because it is at equal distance from previous prime (205305403) and next prime (205305407).

It is not a de Polignac number, because 205305405 - 2¹ = 205305403 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205305403) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 220294 + ... + 221223.

It is an arithmetic number, because the mean of its divisors is an integer number (21192864).

Almost surely, 2^205305405 is an apocalyptic number.

It is an amenable number.

205305405 is a deficient number, since it is larger than the sum of its proper divisors (133780419).

205305405 is a wasteful number, since it uses less digits than its factorization.

205305405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441556.

The product of its (nonzero) digits is 3000, while the sum is 24.

The square root of 205305405 is about 14328.4822992528. The cubic root of 205305405 is about 589.9295185365.

Adding to 205305405 its reverse (504503502), we get a palindrome (709808907).

The spelling of 205305405 in words is "two hundred five million, three hundred five thousand, four hundred five".