21183648449 has 2 divisors, whose sum is σ = 21183648450. Its totient is φ = 21183648448.

The previous prime is 21183648389. The next prime is 21183648463. The reversal of 21183648449 is 94484638112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21182764849 + 883600 = 145543^2 + 940^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21183648449 is a prime.

It is a super-2 number, since 2×21183648449² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21183648397 and 21183648406.

It is not a weakly prime, because it can be changed into another prime (21183648149) 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, 10591824224 + 10591824225.

It is an arithmetic number, because the mean of its divisors is an integer number (10591824225).

Almost surely, 2^21183648449 is an apocalyptic number.

It is an amenable number.

21183648449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21183648449 is an equidigital number, since it uses as much as digits as its factorization.

21183648449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1327104, while the sum is 50.

The spelling of 21183648449 in words is "twenty-one billion, one hundred eighty-three million, six hundred forty-eight thousand, four hundred forty-nine".