21600550205 has 16 divisors (see below), whose sum is σ = 27925475760. Its totient is φ = 15944936448.

The previous prime is 21600550193. The next prime is 21600550247. The reversal of 21600550205 is 50205500612.

It can be written as a sum of positive squares in 8 ways, for example, as 3564328804 + 18036221401 = 59702^2 + 134299^2 .

It is a cyclic number.

It is not a de Polignac number, because 21600550205 - 2⁴ = 21600550189 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105899 + ... + 233271.

It is an arithmetic number, because the mean of its divisors is an integer number (1745342235).

Almost surely, 2^21600550205 is an apocalyptic number.

It is an amenable number.

21600550205 is a deficient number, since it is larger than the sum of its proper divisors (6324925555).

21600550205 is a wasteful number, since it uses less digits than its factorization.

21600550205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130000.

The product of its (nonzero) digits is 3000, while the sum is 26.

The spelling of 21600550205 in words is "twenty-one billion, six hundred million, five hundred fifty thousand, two hundred five".