205012510243 has 4 divisors (see below), whose sum is σ = 205671714768. Its totient is φ = 204353305720.

The previous prime is 205012510229. The next prime is 205012510267. The reversal of 205012510243 is 342015210502.

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 205012510243 - 2³³ = 196422575651 is a prime.

It is a super-2 number, since 2×205012510243² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205012510643) 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, 329601796 + ... + 329602417.

It is an arithmetic number, because the mean of its divisors is an integer number (51417928692).

Almost surely, 2^205012510243 is an apocalyptic number.

205012510243 is a deficient number, since it is larger than the sum of its proper divisors (659204525).

205012510243 is an equidigital number, since it uses as much as digits as its factorization.

205012510243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659204524.

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 205012510243 its reverse (342015210502), we get a palindrome (547027720745).

The spelling of 205012510243 in words is "two hundred five billion, twelve million, five hundred ten thousand, two hundred forty-three".