817135682891 has 4 divisors (see below), whose sum is σ = 891420744984. Its totient is φ = 742850620800.

The previous prime is 817135682873. The next prime is 817135682897. The reversal of 817135682891 is 198286531718.

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

It is a cyclic number.

It is not a de Polignac number, because 817135682891 - 2¹⁴ = 817135666507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 817135682891.

It is not an unprimeable number, because it can be changed into a prime (817135682897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37142531030 + ... + 37142531051.

It is an arithmetic number, because the mean of its divisors is an integer number (222855186246).

Almost surely, 2^817135682891 is an apocalyptic number.

817135682891 is a deficient number, since it is larger than the sum of its proper divisors (74285062093).

817135682891 is a wasteful number, since it uses less digits than its factorization.

817135682891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74285062092.

The product of its digits is 5806080, while the sum is 59.

The spelling of 817135682891 in words is "eight hundred seventeen billion, one hundred thirty-five million, six hundred eighty-two thousand, eight hundred ninety-one".