1817916505553 has 2 divisors, whose sum is σ = 1817916505554. Its totient is φ = 1817916505552.

The previous prime is 1817916505507. The next prime is 1817916505597. The reversal of 1817916505553 is 3555056197181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1533802987024 + 284113518529 = 1238468^2 + 533023^2 .

It is a cyclic number.

It is not a de Polignac number, because 1817916505553 - 2⁴⁰ = 718404877777 is a prime.

It is not a weakly prime, because it can be changed into another prime (1817916505753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 908958252776 + 908958252777.

It is an arithmetic number, because the mean of its divisors is an integer number (908958252777).

Almost surely, 2^{1817916505553} is an apocalyptic number.

It is an amenable number.

1817916505553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1817916505553 is an equidigital number, since it uses as much as digits as its factorization.

1817916505553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5670000, while the sum is 56.

The spelling of 1817916505553 in words is "one trillion, eight hundred seventeen billion, nine hundred sixteen million, five hundred five thousand, five hundred fifty-three".