21010203 has 24 divisors (see below), whose sum is σ = 31145712. Its totient is φ = 13644288.

The previous prime is 21010193. The next prime is 21010217. The reversal of 21010203 is 30201012.

It is a happy number.

It is not a de Polignac number, because 21010203 - 2⁹ = 21009691 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21010403) 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 23 ways as a sum of consecutive naturals, for example, 74100 + ... + 74382.

It is an arithmetic number, because the mean of its divisors is an integer number (1297738).

Almost surely, 2^21010203 is an apocalyptic number.

21010203 is a deficient number, since it is larger than the sum of its proper divisors (10135509).

21010203 is a wasteful number, since it uses less digits than its factorization.

21010203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 21010203 is about 4583.6887983370. The cubic root of 21010203 is about 275.9370918377.

Adding to 21010203 its reverse (30201012), we get a palindrome (51211215).

The spelling of 21010203 in words is "twenty-one million, ten thousand, two hundred three".