518564221793 has 2 divisors, whose sum is σ = 518564221794. Its totient is φ = 518564221792.

The previous prime is 518564221783. The next prime is 518564221807. The reversal of 518564221793 is 397122465815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 398232937249 + 120331284544 = 631057^2 + 346888^2 .

It is a cyclic number.

It is not a de Polignac number, because 518564221793 - 2⁶ = 518564221729 is a prime.

It is a super-2 number, since 2×518564221793² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (518564221783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259282110896 + 259282110897.

It is an arithmetic number, because the mean of its divisors is an integer number (259282110897).

Almost surely, 2^518564221793 is an apocalyptic number.

It is an amenable number.

518564221793 is a deficient number, since it is larger than the sum of its proper divisors (1).

518564221793 is an equidigital number, since it uses as much as digits as its factorization.

518564221793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3628800, while the sum is 53.

The spelling of 518564221793 in words is "five hundred eighteen billion, five hundred sixty-four million, two hundred twenty-one thousand, seven hundred ninety-three".