1818539997385 has 4 divisors (see below), whose sum is σ = 2182247996868. Its totient is φ = 1454831997904.

The previous prime is 1818539997353. The next prime is 1818539997401. The reversal of 1818539997385 is 5837999358181.

1818539997385 = 953556² + 953557².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 909270952249 + 909269045136 = 953557^2 + 953556^2 .

It is a cyclic number.

It is not a de Polignac number, because 1818539997385 - 2⁵ = 1818539997353 is a prime.

It is a Smith number, since the sum of its digits (76) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181853999734 + ... + 181853999743.

It is an arithmetic number, because the mean of its divisors is an integer number (545561999217).

Almost surely, 2^{1818539997385} is an apocalyptic number.

1818539997385 is the 953557-th centered square number.

It is an amenable number.

1818539997385 is a deficient number, since it is larger than the sum of its proper divisors (363707999483).

1818539997385 is an equidigital number, since it uses as much as digits as its factorization.

1818539997385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363707999482.

The product of its digits is 587865600, while the sum is 76.

The spelling of 1818539997385 in words is "one trillion, eight hundred eighteen billion, five hundred thirty-nine million, nine hundred ninety-seven thousand, three hundred eighty-five".