21200540205 has 16 divisors (see below), whose sum is σ = 36530161920. Its totient is φ = 10437188928.

The previous prime is 21200540189. The next prime is 21200540261. The reversal of 21200540205 is 50204500212.

It is a happy number.

It is not a de Polignac number, because 21200540205 - 2⁴ = 21200540189 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54360165 + ... + 54360554.

It is an arithmetic number, because the mean of its divisors is an integer number (2283135120).

Almost surely, 2^21200540205 is an apocalyptic number.

It is an amenable number.

21200540205 is a deficient number, since it is larger than the sum of its proper divisors (15329621715).

21200540205 is a wasteful number, since it uses less digits than its factorization.

21200540205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108720740.

The product of its (nonzero) digits is 800, while the sum is 21.

The spelling of 21200540205 in words is "twenty-one billion, two hundred million, five hundred forty thousand, two hundred five".