817321742543 has 4 divisors (see below), whose sum is σ = 817472573160. Its totient is φ = 817170911928.

The previous prime is 817321742539. The next prime is 817321742579. The reversal of 817321742543 is 345247123718.

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 817321742543 - 2² = 817321742539 is a prime.

It is a super-2 number, since 2×817321742543² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (817321742513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75407180 + ... + 75418017.

It is an arithmetic number, because the mean of its divisors is an integer number (204368143290).

Almost surely, 2^817321742543 is an apocalyptic number.

817321742543 is a deficient number, since it is larger than the sum of its proper divisors (150830617).

817321742543 is a wasteful number, since it uses less digits than its factorization.

817321742543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150830616.

The product of its digits is 1128960, while the sum is 47.

The spelling of 817321742543 in words is "eight hundred seventeen billion, three hundred twenty-one million, seven hundred forty-two thousand, five hundred forty-three".