21004400203 has 2 divisors, whose sum is σ = 21004400204. Its totient is φ = 21004400202.

The previous prime is 21004400141. The next prime is 21004400279. The reversal of 21004400203 is 30200440012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21004400203 - 2²¹ = 21002303051 is a prime.

It is not a weakly prime, because it can be changed into another prime (21004409203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502200101 + 10502200102.

It is an arithmetic number, because the mean of its divisors is an integer number (10502200102).

Almost surely, 2^21004400203 is an apocalyptic number.

21004400203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004400203 is an equidigital number, since it uses as much as digits as its factorization.

21004400203 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 16.

Adding to 21004400203 its reverse (30200440012), we get a palindrome (51204840215).

The spelling of 21004400203 in words is "twenty-one billion, four million, four hundred thousand, two hundred three".