686793944257 has 8 divisors (see below), whose sum is σ = 687359342120. Its totient is φ = 686228647680.

The previous prime is 686793944189. The next prime is 686793944297. The reversal of 686793944257 is 752449397686.

It can be written as a sum of positive squares in 4 ways, for example, as 322015391296 + 364778552961 = 567464^2 + 603969^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686793944257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686793944297) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19555369 + ... + 19590457.

It is an arithmetic number, because the mean of its divisors is an integer number (85919917765).

Almost surely, 2^686793944257 is an apocalyptic number.

It is an amenable number.

686793944257 is a deficient number, since it is larger than the sum of its proper divisors (565397863).

686793944257 is a wasteful number, since it uses less digits than its factorization.

686793944257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50643.

The product of its digits is 548674560, while the sum is 70.

It can be divided in two parts, 6867939 and 44257, that added together give a palindrome (6912196).

The spelling of 686793944257 in words is "six hundred eighty-six billion, seven hundred ninety-three million, nine hundred forty-four thousand, two hundred fifty-seven".