21304055503 has 2 divisors, whose sum is σ = 21304055504. Its totient is φ = 21304055502.

The previous prime is 21304055477. The next prime is 21304055527. The reversal of 21304055503 is 30555040312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21304055503 - 2¹³ = 21304047311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21304055803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10652027751 + 10652027752.

It is an arithmetic number, because the mean of its divisors is an integer number (10652027752).

Almost surely, 2^21304055503 is an apocalyptic number.

21304055503 is a deficient number, since it is larger than the sum of its proper divisors (1).

21304055503 is an equidigital number, since it uses as much as digits as its factorization.

21304055503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 28.

Adding to 21304055503 its reverse (30555040312), we get a palindrome (51859095815).

The spelling of 21304055503 in words is "twenty-one billion, three hundred four million, fifty-five thousand, five hundred three".