205309873 has 4 divisors (see below), whose sum is σ = 205477888. Its totient is φ = 205141860.

The previous prime is 205309849. The next prime is 205309883. The reversal of 205309873 is 378903502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205309873 is a prime.

It is a super-2 number, since 2×205309873² = 84304287902552258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205309823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82161 + ... + 84622.

It is an arithmetic number, because the mean of its divisors is an integer number (51369472).

Almost surely, 2^205309873 is an apocalyptic number.

It is an amenable number.

205309873 is a deficient number, since it is larger than the sum of its proper divisors (168015).

205309873 is a wasteful number, since it uses less digits than its factorization.

205309873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168014.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 205309873 is about 14328.6382116376. The cubic root of 205309873 is about 589.9337979919.

It can be divided in two parts, 20530 and 9873, that added together give a palindrome (30403).

The spelling of 205309873 in words is "two hundred five million, three hundred nine thousand, eight hundred seventy-three".