205625621 has 2 divisors, whose sum is σ = 205625622. Its totient is φ = 205625620.

The previous prime is 205625603. The next prime is 205625627. The reversal of 205625621 is 126526502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 199798225 + 5827396 = 14135^2 + 2414^2 .

It is a cyclic number.

It is not a de Polignac number, because 205625621 - 2²⁶ = 138516757 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205625627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102812810 + 102812811.

It is an arithmetic number, because the mean of its divisors is an integer number (102812811).

Almost surely, 2^205625621 is an apocalyptic number.

It is an amenable number.

205625621 is a deficient number, since it is larger than the sum of its proper divisors (1).

205625621 is an equidigital number, since it uses as much as digits as its factorization.

205625621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 205625621 is about 14339.6520529614. The cubic root of 205625621 is about 590.2360646853.

The spelling of 205625621 in words is "two hundred five million, six hundred twenty-five thousand, six hundred twenty-one".