21100103 has 2 divisors, whose sum is σ = 21100104. Its totient is φ = 21100102.

The previous prime is 21100097. The next prime is 21100129. The reversal of 21100103 is 30100112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21100103 - 2⁴ = 21100087 is a prime.

It is a super-2 number, since 2×21100103² = 890428693221218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100193) 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 as a sum of consecutive naturals, namely, 10550051 + 10550052.

It is an arithmetic number, because the mean of its divisors is an integer number (10550052).

Almost surely, 2^21100103 is an apocalyptic number.

21100103 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100103 is an equidigital number, since it uses as much as digits as its factorization.

21100103 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 21100103 is about 4593.4848426875. The cubic root of 21100103 is about 276.3300984607.

Adding to 21100103 its reverse (30100112), we get a palindrome (51200215).

Subtracting 21100103 from its reverse (30100112), we obtain a palindrome (9000009).

The spelling of 21100103 in words is "twenty-one million, one hundred thousand, one hundred three".