21054552205 has 16 divisors (see below), whose sum is σ = 25390076400. Its totient is φ = 16760659968.

The previous prime is 21054552191. The next prime is 21054552227. The reversal of 21054552205 is 50225545012.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 10143914089 + 10910638116 = 100717^2 + 104454^2 .

It is a cyclic number.

It is not a de Polignac number, because 21054552205 - 2²⁵ = 21020997773 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, 2177221 + ... + 2186869.

It is an arithmetic number, because the mean of its divisors is an integer number (1586879775).

Almost surely, 2^21054552205 is an apocalyptic number.

It is an amenable number.

21054552205 is a deficient number, since it is larger than the sum of its proper divisors (4335524195).

21054552205 is a wasteful number, since it uses less digits than its factorization.

21054552205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11760.

The product of its (nonzero) digits is 20000, while the sum is 31.

The spelling of 21054552205 in words is "twenty-one billion, fifty-four million, five hundred fifty-two thousand, two hundred five".