21042103 has 2 divisors, whose sum is σ = 21042104. Its totient is φ = 21042102.

The previous prime is 21042097. The next prime is 21042127. The reversal of 21042103 is 30124012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21042103 - 2¹³ = 21033911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21042193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521051 + 10521052.

It is an arithmetic number, because the mean of its divisors is an integer number (10521052).

Almost surely, 2^21042103 is an apocalyptic number.

21042103 is a deficient number, since it is larger than the sum of its proper divisors (1).

21042103 is an equidigital number, since it uses as much as digits as its factorization.

21042103 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21042103 is about 4587.1672086376. The cubic root of 21042103 is about 276.0766738948.

Adding to 21042103 its reverse (30124012), we get a palindrome (51166115).

The spelling of 21042103 in words is "twenty-one million, forty-two thousand, one hundred three".