21304440473 has 2 divisors, whose sum is σ = 21304440474. Its totient is φ = 21304440472.

The previous prime is 21304440397. The next prime is 21304440539. The reversal of 21304440473 is 37404440312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20092495504 + 1211944969 = 141748^2 + 34813^2 .

It is a cyclic number.

It is not a de Polignac number, because 21304440473 - 2¹⁰ = 21304439449 is a prime.

It is not a weakly prime, because it can be changed into another prime (21304410473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10652220236 + 10652220237.

It is an arithmetic number, because the mean of its divisors is an integer number (10652220237).

Almost surely, 2^21304440473 is an apocalyptic number.

It is an amenable number.

21304440473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21304440473 is an equidigital number, since it uses as much as digits as its factorization.

21304440473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 32.

Adding to 21304440473 its reverse (37404440312), we get a palindrome (58708880785).

The spelling of 21304440473 in words is "twenty-one billion, three hundred four million, four hundred forty thousand, four hundred seventy-three".