205017004421 has 2 divisors, whose sum is σ = 205017004422. Its totient is φ = 205017004420.

The previous prime is 205017004391. The next prime is 205017004427. The reversal of 205017004421 is 124400710502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165660396196 + 39356608225 = 407014^2 + 198385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205017004421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205017004427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102508502210 + 102508502211.

It is an arithmetic number, because the mean of its divisors is an integer number (102508502211).

Almost surely, 2^205017004421 is an apocalyptic number.

It is an amenable number.

205017004421 is a deficient number, since it is larger than the sum of its proper divisors (1).

205017004421 is an equidigital number, since it uses as much as digits as its factorization.

205017004421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 26.

Adding to 205017004421 its reverse (124400710502), we get a palindrome (329417714923).

The spelling of 205017004421 in words is "two hundred five billion, seventeen million, four thousand, four hundred twenty-one".