205430251 has 4 divisors (see below), whose sum is σ = 221232592. Its totient is φ = 189627912.

The previous prime is 205430243. The next prime is 205430297. The reversal of 205430251 is 152034502.

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 205430251 - 2³ = 205430243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205430231) 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, 7901151 + ... + 7901176.

It is an arithmetic number, because the mean of its divisors is an integer number (55308148).

Almost surely, 2^205430251 is an apocalyptic number.

205430251 is a deficient number, since it is larger than the sum of its proper divisors (15802341).

205430251 is a wasteful number, since it uses less digits than its factorization.

205430251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15802340.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 205430251 is about 14332.8382046265. The cubic root of 205430251 is about 590.0490728119.

Adding to 205430251 its reverse (152034502), we get a palindrome (357464753).

The spelling of 205430251 in words is "two hundred five million, four hundred thirty thousand, two hundred fifty-one".