21365564460193 has 2 divisors, whose sum is σ = 21365564460194. Its totient is φ = 21365564460192.

The previous prime is 21365564460173. The next prime is 21365564460241. The reversal of 21365564460193 is 39106446556312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20643501294144 + 722063166049 = 4543512^2 + 849743^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21365564460193 is a prime.

It is not a weakly prime, because it can be changed into another prime (21365564460113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682782230096 + 10682782230097.

It is an arithmetic number, because the mean of its divisors is an integer number (10682782230097).

Almost surely, 2^{21365564460193} is an apocalyptic number.

It is an amenable number.

21365564460193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21365564460193 is an equidigital number, since it uses as much as digits as its factorization.

21365564460193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13996800, while the sum is 55.

The spelling of 21365564460193 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred sixty-four million, four hundred sixty thousand, one hundred ninety-three".