205439243 has 4 divisors (see below), whose sum is σ = 214371408. Its totient is φ = 196507080.

The previous prime is 205439231. The next prime is 205439249. The reversal of 205439243 is 342934502.

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

It is a cyclic number.

It is not a de Polignac number, because 205439243 - 2¹² = 205435147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205439249) 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, 4466048 + ... + 4466093.

It is an arithmetic number, because the mean of its divisors is an integer number (53592852).

Almost surely, 2^205439243 is an apocalyptic number.

205439243 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

205439243 is a deficient number, since it is larger than the sum of its proper divisors (8932165).

205439243 is an equidigital number, since it uses as much as digits as its factorization.

205439243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8932164.

The product of its (nonzero) digits is 25920, while the sum is 32.

The square root of 205439243 is about 14333.1518864484. The cubic root of 205439243 is about 590.0576818066.

The spelling of 205439243 in words is "two hundred five million, four hundred thirty-nine thousand, two hundred forty-three".