205021643401 has 2 divisors, whose sum is σ = 205021643402. Its totient is φ = 205021643400.

The previous prime is 205021643381. The next prime is 205021643417. The reversal of 205021643401 is 104346120502.

205021643401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169546297600 + 35475345801 = 411760^2 + 188349^2 .

It is a cyclic number.

It is not a de Polignac number, because 205021643401 - 2³¹ = 202874159753 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205021643401.

It is not a weakly prime, because it can be changed into another prime (205021643461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102510821700 + 102510821701.

It is an arithmetic number, because the mean of its divisors is an integer number (102510821701).

Almost surely, 2^205021643401 is an apocalyptic number.

It is an amenable number.

205021643401 is a deficient number, since it is larger than the sum of its proper divisors (1).

205021643401 is an equidigital number, since it uses as much as digits as its factorization.

205021643401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 28.

Adding to 205021643401 its reverse (104346120502), we get a palindrome (309367763903).

The spelling of 205021643401 in words is "two hundred five billion, twenty-one million, six hundred forty-three thousand, four hundred one".