205655221 has 24 divisors (see below), whose sum is σ = 228263040. Its totient is φ = 184677120.

The previous prime is 205655207. The next prime is 205655231. The reversal of 205655221 is 122556502.

It is a de Polignac number, because none of the positive numbers 2^k-205655221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205655221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205655201) 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 in 23 ways as a sum of consecutive naturals, for example, 1501065 + ... + 1501201.

It is an arithmetic number, because the mean of its divisors is an integer number (9510960).

Almost surely, 2^205655221 is an apocalyptic number.

It is an amenable number.

205655221 is a deficient number, since it is larger than the sum of its proper divisors (22607819).

205655221 is a wasteful number, since it uses less digits than its factorization.

205655221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 205655221 is about 14340.6841189673. The cubic root of 205655221 is about 590.2643850039.

The spelling of 205655221 in words is "two hundred five million, six hundred fifty-five thousand, two hundred twenty-one".