21648064901 has 2 divisors, whose sum is σ = 21648064902. Its totient is φ = 21648064900.

The previous prime is 21648064859. The next prime is 21648064909. The reversal of 21648064901 is 10946084612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17568177025 + 4079887876 = 132545^2 + 63874^2 .

It is a cyclic number.

It is not a de Polignac number, because 21648064901 - 2¹⁴ = 21648048517 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21648064909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10824032450 + 10824032451.

It is an arithmetic number, because the mean of its divisors is an integer number (10824032451).

Almost surely, 2^21648064901 is an apocalyptic number.

It is an amenable number.

21648064901 is a deficient number, since it is larger than the sum of its proper divisors (1).

21648064901 is an equidigital number, since it uses as much as digits as its factorization.

21648064901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 41.

The spelling of 21648064901 in words is "twenty-one billion, six hundred forty-eight million, sixty-four thousand, nine hundred one".