205345405 has 8 divisors (see below), whose sum is σ = 247776984. Its totient is φ = 163368000.

The previous prime is 205345391. The next prime is 205345421. The reversal of 205345405 is 504543502.

It can be written as a sum of positive squares in 4 ways, for example, as 17189316 + 188156089 = 4146^2 + 13717^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 205345405 - 2¹³ = 205337213 is a prime.

It is a super-2 number, since 2×205345405² = 84333470709228050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112546 + ... + 114355.

It is an arithmetic number, because the mean of its divisors is an integer number (30972123).

Almost surely, 2^205345405 is an apocalyptic number.

It is an amenable number.

205345405 is a deficient number, since it is larger than the sum of its proper divisors (42431579).

205345405 is a wasteful number, since it uses less digits than its factorization.

205345405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227087.

The product of its (nonzero) digits is 12000, while the sum is 28.

The square root of 205345405 is about 14329.8780525167. The cubic root of 205345405 is about 589.9678283712.

Adding to 205345405 its reverse (504543502), we get a palindrome (709888907).

The spelling of 205345405 in words is "two hundred five million, three hundred forty-five thousand, four hundred five".