21711203 has 4 divisors (see below), whose sum is σ = 21741168. Its totient is φ = 21681240.

The previous prime is 21711163. The next prime is 21711229. The reversal of 21711203 is 30211712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21711203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21711803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13868 + ... + 15353.

It is an arithmetic number, because the mean of its divisors is an integer number (5435292).

Almost surely, 2^21711203 is an apocalyptic number.

21711203 is a deficient number, since it is larger than the sum of its proper divisors (29965).

21711203 is an equidigital number, since it uses as much as digits as its factorization.

21711203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29964.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21711203 is about 4659.5281950000. The cubic root of 21711203 is about 278.9724368226.

Adding to 21711203 its reverse (30211712), we get a palindrome (51922915).

The spelling of 21711203 in words is "twenty-one million, seven hundred eleven thousand, two hundred three".