685715056865 has 4 divisors (see below), whose sum is σ = 822858068244. Its totient is φ = 548572045488.

The previous prime is 685715056849. The next prime is 685715056883. The reversal of 685715056865 is 568650517586.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 495548418304 + 190166638561 = 703952^2 + 436081^2 .

It is a cyclic number.

It is not a de Polignac number, because 685715056865 - 2⁴ = 685715056849 is a prime.

It is a super-2 number, since 2×685715056865² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 685715056798 and 685715056807.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 68571505682 + ... + 68571505691.

It is an arithmetic number, because the mean of its divisors is an integer number (205714517061).

Almost surely, 2^685715056865 is an apocalyptic number.

It is an amenable number.

685715056865 is a deficient number, since it is larger than the sum of its proper divisors (137143011379).

685715056865 is a wasteful number, since it uses less digits than its factorization.

685715056865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137143011378.

The product of its (nonzero) digits is 60480000, while the sum is 62.

The spelling of 685715056865 in words is "six hundred eighty-five billion, seven hundred fifteen million, fifty-six thousand, eight hundred sixty-five".