205561621170 has 48 divisors (see below), whose sum is σ = 557697621312. Its totient is φ = 52433108640.

The previous prime is 205561621151. The next prime is 205561621247. The reversal of 205561621170 is 71126165502.

205561621170 is a `hidden beast` number, since 2 + 0 + 5 + 5 + 616 + 21 + 17 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49650496 + ... + 49654635.

It is an arithmetic number, because the mean of its divisors is an integer number (11618700444).

Almost surely, 2^205561621170 is an apocalyptic number.

205561621170 is an abundant number, since it is smaller than the sum of its proper divisors (352136000142).

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

205561621170 is a wasteful number, since it uses less digits than its factorization.

205561621170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99305167 (or 99305164 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

Adding to 205561621170 its reverse (71126165502), we get a palindrome (276687786672).

The spelling of 205561621170 in words is "two hundred five billion, five hundred sixty-one million, six hundred twenty-one thousand, one hundred seventy".