21035205 has 48 divisors (see below), whose sum is σ = 39896064. Its totient is φ = 10206720.

The previous prime is 21035197. The next prime is 21035207. The reversal of 21035205 is 50253012.

It is a happy number.

It is not a de Polignac number, because 21035205 - 2³ = 21035197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21035207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23272 + ... + 24158.

It is an arithmetic number, because the mean of its divisors is an integer number (831168).

Almost surely, 2^21035205 is an apocalyptic number.

It is an amenable number.

21035205 is a deficient number, since it is larger than the sum of its proper divisors (18860859).

21035205 is a wasteful number, since it uses less digits than its factorization.

21035205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 946 (or 943 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 21035205 is about 4586.4152668506. The cubic root of 21035205 is about 276.0465028764.

Adding to 21035205 its reverse (50253012), we get a palindrome (71288217).

The spelling of 21035205 in words is "twenty-one million, thirty-five thousand, two hundred five".