21235550205 has 16 divisors (see below), whose sum is σ = 34028928000. Its totient is φ = 11308277568.

The previous prime is 21235550113. The next prime is 21235550251. The reversal of 21235550205 is 50205553212.

It is not a de Polignac number, because 21235550205 - 2¹⁷ = 21235419133 is a prime.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 1074205 + ... + 1093794.

It is an arithmetic number, because the mean of its divisors is an integer number (2126808000).

Almost surely, 2^21235550205 is an apocalyptic number.

It is an amenable number.

21235550205 is a deficient number, since it is larger than the sum of its proper divisors (12793377795).

21235550205 is a wasteful number, since it uses less digits than its factorization.

21235550205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2168660.

The product of its (nonzero) digits is 15000, while the sum is 30.

The spelling of 21235550205 in words is "twenty-one billion, two hundred thirty-five million, five hundred fifty thousand, two hundred five".