21004102403 has 2 divisors, whose sum is σ = 21004102404. Its totient is φ = 21004102402.

The previous prime is 21004102381. The next prime is 21004102417. The reversal of 21004102403 is 30420140012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21004102403 - 2³⁰ = 19930360579 is a prime.

It is not a weakly prime, because it can be changed into another prime (21004102453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502051201 + 10502051202.

It is an arithmetic number, because the mean of its divisors is an integer number (10502051202).

Almost surely, 2^21004102403 is an apocalyptic number.

21004102403 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004102403 is an equidigital number, since it uses as much as digits as its factorization.

21004102403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21004102403 its reverse (30420140012), we get a palindrome (51424242415).

The spelling of 21004102403 in words is "twenty-one billion, four million, one hundred two thousand, four hundred three".