21500553332205 has 48 divisors (see below), whose sum is σ = 37632163745280. Its totient is φ = 11354812326144.

The previous prime is 21500553332179. The next prime is 21500553332227. The reversal of 21500553332205 is 50223335500512.

21500553332205 is a `hidden beast` number, since 2 + 1 + 50 + 0 + 55 + 333 + 220 + 5 = 666.

It is not a de Polignac number, because 21500553332205 - 2¹⁴ = 21500553315821 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21500553332205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 66949977 + ... + 67270353.

It is an arithmetic number, because the mean of its divisors is an integer number (784003411360).

Almost surely, 2^{21500553332205} is an apocalyptic number.

It is an amenable number.

21500553332205 is a deficient number, since it is larger than the sum of its proper divisors (16131610413075).

21500553332205 is a wasteful number, since it uses less digits than its factorization.

21500553332205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334970 (or 334967 counting only the distinct ones).

The product of its (nonzero) digits is 135000, while the sum is 36.

Adding to 21500553332205 its reverse (50223335500512), we get a palindrome (71723888832717).

The spelling of 21500553332205 in words is "twenty-one trillion, five hundred billion, five hundred fifty-three million, three hundred thirty-two thousand, two hundred five".