205144421 has 2 divisors, whose sum is σ = 205144422. Its totient is φ = 205144420.

The previous prime is 205144417. The next prime is 205144439. The reversal of 205144421 is 124441502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145684900 + 59459521 = 12070^2 + 7711^2 .

It is a cyclic number.

It is not a de Polignac number, because 205144421 - 2² = 205144417 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205144411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102572210 + 102572211.

It is an arithmetic number, because the mean of its divisors is an integer number (102572211).

Almost surely, 2^205144421 is an apocalyptic number.

It is an amenable number.

205144421 is a deficient number, since it is larger than the sum of its proper divisors (1).

205144421 is an equidigital number, since it uses as much as digits as its factorization.

205144421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 205144421 is about 14322.8635754168. The cubic root of 205144421 is about 589.7752864437.

Adding to 205144421 its reverse (124441502), we get a palindrome (329585923).

The spelling of 205144421 in words is "two hundred five million, one hundred forty-four thousand, four hundred twenty-one".