21110205 has 32 divisors (see below), whose sum is σ = 36089856. Its totient is φ = 10511424.

The previous prime is 21110189. The next prime is 21110227. The reversal of 21110205 is 50201112.

It is not a de Polignac number, because 21110205 - 2⁴ = 21110189 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 (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14124 + ... + 15546.

It is an arithmetic number, because the mean of its divisors is an integer number (1127808).

Almost surely, 2^21110205 is an apocalyptic number.

It is an amenable number.

21110205 is a deficient number, since it is larger than the sum of its proper divisors (14979651).

21110205 is a wasteful number, since it uses less digits than its factorization.

21110205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1497.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21110205 is about 4594.5843119917. The cubic root of 21110205 is about 276.3741905248.

Adding to 21110205 its reverse (50201112), we get a palindrome (71311317).

The spelling of 21110205 in words is "twenty-one million, one hundred ten thousand, two hundred five".