817856634369 has 16 divisors (see below), whose sum is σ = 1137931569792. Its totient is φ = 521511564288.

The previous prime is 817856634307. The next prime is 817856634407. The reversal of 817856634369 is 963436658718.

817856634369 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 817856634369 - 2¹² = 817856630273 is a prime.

It is a super-2 number, since 2×817856634369² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (817856634269) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1678687 + ... + 2110379.

It is an arithmetic number, because the mean of its divisors is an integer number (71120723112).

Almost surely, 2^817856634369 is an apocalyptic number.

It is an amenable number.

817856634369 is a deficient number, since it is larger than the sum of its proper divisors (320074935423).

817856634369 is a wasteful number, since it uses less digits than its factorization.

817856634369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459176.

The product of its digits is 156764160, while the sum is 66.

The spelling of 817856634369 in words is "eight hundred seventeen billion, eight hundred fifty-six million, six hundred thirty-four thousand, three hundred sixty-nine".