21033205 has 32 divisors (see below), whose sum is σ = 27578880. Its totient is φ = 15367680.

The previous prime is 21033203. The next prime is 21033223. The reversal of 21033205 is 50233012.

It is not a de Polignac number, because 21033205 - 2¹ = 21033203 is a prime.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033203) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 356466 + ... + 356524.

It is an arithmetic number, because the mean of its divisors is an integer number (861840).

Almost surely, 2^21033205 is an apocalyptic number.

It is an amenable number.

21033205 is a deficient number, since it is larger than the sum of its proper divisors (6545675).

21033205 is a wasteful number, since it uses less digits than its factorization.

21033205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 21033205 is about 4586.1972264612. The cubic root of 21033205 is about 276.0377538847.

Adding to 21033205 its reverse (50233012), we get a palindrome (71266217).

The spelling of 21033205 in words is "twenty-one million, thirty-three thousand, two hundred five".