21004103 has 8 divisors (see below), whose sum is σ = 21247488. Its totient is φ = 20762464.

The previous prime is 21004099. The next prime is 21004117. The reversal of 21004103 is 30140012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21004103 - 2² = 21004099 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 (21004153) 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 in 7 ways as a sum of consecutive naturals, for example, 54650 + ... + 55032.

It is an arithmetic number, because the mean of its divisors is an integer number (2655936).

Almost surely, 2^21004103 is an apocalyptic number.

21004103 is a deficient number, since it is larger than the sum of its proper divisors (243385).

21004103 is a wasteful number, since it uses less digits than its factorization.

21004103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21004103 is about 4583.0233470931. The cubic root of 21004103 is about 275.9103845091.

Adding to 21004103 its reverse (30140012), we get a palindrome (51144115).

The spelling of 21004103 in words is "twenty-one million, four thousand, one hundred three".