205066621 has 2 divisors, whose sum is σ = 205066622. Its totient is φ = 205066620.

The previous prime is 205066619. The next prime is 205066651. The reversal of 205066621 is 126660502.

205066621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204776100 + 290521 = 14310^2 + 539^2 .

It is a cyclic number.

It is not a de Polignac number, because 205066621 - 2¹ = 205066619 is a prime.

Together with 205066619, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 205066621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205066651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102533310 + 102533311.

It is an arithmetic number, because the mean of its divisors is an integer number (102533311).

Almost surely, 2^205066621 is an apocalyptic number.

It is an amenable number.

205066621 is a deficient number, since it is larger than the sum of its proper divisors (1).

205066621 is an equidigital number, since it uses as much as digits as its factorization.

205066621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 205066621 is about 14320.1473805265. The cubic root of 205066621 is about 589.7007205699.

The spelling of 205066621 in words is "two hundred five million, sixty-six thousand, six hundred twenty-one".