205428217017204 has 36 divisors (see below), whose sum is σ = 519283061362884. Its totient is φ = 68475257465472.

The previous prime is 205428217017203. The next prime is 205428217017209. The reversal of 205428217017204 is 402710712824502.

205428217017204 is a `hidden beast` number, since 2 + 0 + 5 + 428 + 2 + 1 + 7 + 0 + 17 + 204 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 122929108275600 + 82499108741604 = 11087340^2 + 9082902^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 205428217017204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205428217017203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30882067 + ... + 36939930.

Almost surely, 2^{205428217017204} is an apocalyptic number.

It is an amenable number.

205428217017204 is an abundant number, since it is smaller than the sum of its proper divisors (313854844345680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205428217017204 is a wasteful number, since it uses less digits than its factorization.

205428217017204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67906144 (or 67906139 counting only the distinct ones).

The product of its (nonzero) digits is 501760, while the sum is 45.

The spelling of 205428217017204 in words is "two hundred five trillion, four hundred twenty-eight billion, two hundred seventeen million, seventeen thousand, two hundred four".