686800124581 has 2 divisors, whose sum is σ = 686800124582. Its totient is φ = 686800124580.

The previous prime is 686800124579. The next prime is 686800124629. The reversal of 686800124581 is 185421008686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 450185979681 + 236614144900 = 670959^2 + 486430^2 .

It is a cyclic number.

It is not a de Polignac number, because 686800124581 - 2¹ = 686800124579 is a prime.

It is a super-2 number, since 2×686800124581² (a number of 24 digits) contains 22 as substring.

Together with 686800124579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686800124501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343400062290 + 343400062291.

It is an arithmetic number, because the mean of its divisors is an integer number (343400062291).

Almost surely, 2^686800124581 is an apocalyptic number.

It is an amenable number.

686800124581 is a deficient number, since it is larger than the sum of its proper divisors (1).

686800124581 is an equidigital number, since it uses as much as digits as its factorization.

686800124581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 737280, while the sum is 49.

The spelling of 686800124581 in words is "six hundred eighty-six billion, eight hundred million, one hundred twenty-four thousand, five hundred eighty-one".