5181665817085 has 4 divisors (see below), whose sum is σ = 6217998980508. Its totient is φ = 4145332653664.

The previous prime is 5181665817077. The next prime is 5181665817103. The reversal of 5181665817085 is 5807185661815.

It is a happy number.

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 672757567524 + 4508908249561 = 820218^2 + 2123419^2 .

It is a cyclic number.

It is not a de Polignac number, because 5181665817085 - 2³ = 5181665817077 is a prime.

It is a Duffinian number.

It is a congruent 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, 518166581704 + ... + 518166581713.

It is an arithmetic number, because the mean of its divisors is an integer number (1554499745127).

Almost surely, 2^{5181665817085} is an apocalyptic number.

It is an amenable number.

5181665817085 is a deficient number, since it is larger than the sum of its proper divisors (1036333163423).

5181665817085 is a wasteful number, since it uses less digits than its factorization.

5181665817085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036333163422.

The product of its (nonzero) digits is 16128000, while the sum is 61.

The spelling of 5181665817085 in words is "five trillion, one hundred eighty-one billion, six hundred sixty-five million, eight hundred seventeen thousand, eighty-five".