21143000205 has 12 divisors (see below), whose sum is σ = 36647867100. Its totient is φ = 11276266752.

The previous prime is 21143000183. The next prime is 21143000213. The reversal of 21143000205 is 50200034112.

21143000205 is a `hidden beast` number, since 211 + 430 + 0 + 0 + 20 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16448832009 + 4694168196 = 128253^2 + 68514^2 .

It is not a de Polignac number, because 21143000205 - 2⁵ = 21143000173 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 234922180 + ... + 234922269.

It is an arithmetic number, because the mean of its divisors is an integer number (3053988925).

Almost surely, 2^21143000205 is an apocalyptic number.

It is an amenable number.

21143000205 is a deficient number, since it is larger than the sum of its proper divisors (15504866895).

21143000205 is a wasteful number, since it uses less digits than its factorization.

21143000205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469844460 (or 469844457 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

Adding to 21143000205 its reverse (50200034112), we get a palindrome (71343034317).

The spelling of 21143000205 in words is "twenty-one billion, one hundred forty-three million, two hundred five", and thus it is an aban number.