205054315421 has 2 divisors, whose sum is σ = 205054315422. Its totient is φ = 205054315420.

The previous prime is 205054315381. The next prime is 205054315481. The reversal of 205054315421 is 124513450502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 186288055321 + 18766260100 = 431611^2 + 136990^2 .

It is a cyclic number.

It is not a de Polignac number, because 205054315421 - 2²² = 205050121117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205054315481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102527157710 + 102527157711.

It is an arithmetic number, because the mean of its divisors is an integer number (102527157711).

Almost surely, 2^205054315421 is an apocalyptic number.

It is an amenable number.

205054315421 is a deficient number, since it is larger than the sum of its proper divisors (1).

205054315421 is an equidigital number, since it uses as much as digits as its factorization.

205054315421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 205054315421 its reverse (124513450502), we get a palindrome (329567765923).

The spelling of 205054315421 in words is "two hundred five billion, fifty-four million, three hundred fifteen thousand, four hundred twenty-one".