21116203 has 2 divisors, whose sum is σ = 21116204. Its totient is φ = 21116202.

The previous prime is 21116191. The next prime is 21116209. The reversal of 21116203 is 30261112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21116203 is a prime.

It is not a weakly prime, because it can be changed into another prime (21116209) 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 as a sum of consecutive naturals, namely, 10558101 + 10558102.

It is an arithmetic number, because the mean of its divisors is an integer number (10558102).

Almost surely, 2^21116203 is an apocalyptic number.

21116203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21116203 is an equidigital number, since it uses as much as digits as its factorization.

21116203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21116203 is about 4595.2369906241. The cubic root of 21116203 is about 276.4003632601.

Adding to 21116203 its reverse (30261112), we get a palindrome (51377315).

The spelling of 21116203 in words is "twenty-one million, one hundred sixteen thousand, two hundred three".