21317103 has 6 divisors (see below), whose sum is σ = 30791384. Its totient is φ = 14211396.

The previous prime is 21317083. The next prime is 21317129. The reversal of 21317103 is 30171312.

It is not a de Polignac number, because 21317103 - 2⁶ = 21317039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21317003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1184275 + ... + 1184292.

Almost surely, 2^21317103 is an apocalyptic number.

21317103 is a deficient number, since it is larger than the sum of its proper divisors (9474281).

21317103 is a wasteful number, since it uses less digits than its factorization.

21317103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2368573 (or 2368570 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 21317103 is about 4617.0448340903. The cubic root of 21317103 is about 277.2741576172.

Adding to 21317103 its reverse (30171312), we get a palindrome (51488415).

The spelling of 21317103 in words is "twenty-one million, three hundred seventeen thousand, one hundred three".