685318181256 has 24 divisors (see below), whose sum is σ = 1856070074430. Its totient is φ = 228439393728.

The previous prime is 685318181239. The next prime is 685318181287. The reversal of 685318181256 is 652181813586.

685318181256 is a `hidden beast` number, since 6 + 8 + 531 + 8 + 1 + 81 + 25 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 683548632900 + 1769548356 = 826770^2 + 42066^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×685318181256² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4759153965 + ... + 4759154108.

Almost surely, 2^685318181256 is an apocalyptic number.

It is an amenable number.

685318181256 is an abundant number, since it is smaller than the sum of its proper divisors (1170751893174).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

685318181256 is a wasteful number, since it uses less digits than its factorization.

685318181256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9518308085 (or 9518308078 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 54.

The spelling of 685318181256 in words is "six hundred eighty-five billion, three hundred eighteen million, one hundred eighty-one thousand, two hundred fifty-six".