21568280893 has 2 divisors, whose sum is σ = 21568280894. Its totient is φ = 21568280892.

The previous prime is 21568280819. The next prime is 21568280917. The reversal of 21568280893 is 39808286512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15579533124 + 5988747769 = 124818^2 + 77387^2 .

It is a cyclic number.

It is not a de Polignac number, because 21568280893 - 2²¹ = 21566183741 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21568280893.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21568280593) 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, 10784140446 + 10784140447.

It is an arithmetic number, because the mean of its divisors is an integer number (10784140447).

Almost surely, 2^21568280893 is an apocalyptic number.

It is an amenable number.

21568280893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21568280893 is an equidigital number, since it uses as much as digits as its factorization.

21568280893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1658880, while the sum is 52.

The spelling of 21568280893 in words is "twenty-one billion, five hundred sixty-eight million, two hundred eighty thousand, eight hundred ninety-three".