21101203 has 4 divisors (see below), whose sum is σ = 21110400. Its totient is φ = 21092008.

The previous prime is 21101123. The next prime is 21101207. The reversal of 21101203 is 30210112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21101203 - 2¹³ = 21093011 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21101203.

It is not an unprimeable number, because it can be changed into a prime (21101207) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1998 + ... + 6796.

It is an arithmetic number, because the mean of its divisors is an integer number (5277600).

Almost surely, 2^21101203 is an apocalyptic number.

21101203 is a deficient number, since it is larger than the sum of its proper divisors (9197).

21101203 is an equidigital number, since it uses as much as digits as its factorization.

21101203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9196.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21101203 is about 4593.6045759295. The cubic root of 21101203 is about 276.3349002986.

Adding to 21101203 its reverse (30210112), we get a palindrome (51311315).

The spelling of 21101203 in words is "twenty-one million, one hundred one thousand, two hundred three".