685012538016 has 144 divisors (see below), whose sum is σ = 1981307601000. Its totient is φ = 224465485824.

The previous prime is 685012538011. The next prime is 685012538051. The reversal of 685012538016 is 610835210586.

685012538016 is a `hidden beast` number, since 6 + 8 + 501 + 2 + 53 + 80 + 16 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 385387673616 + 299624864400 = 620796^2 + 547380^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (685012538011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4080180 + ... + 4244748.

Almost surely, 2^685012538016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685012538016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (990653800500).

685012538016 is an abundant number, since it is smaller than the sum of its proper divisors (1296295062984).

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

685012538016 is a wasteful number, since it uses less digits than its factorization.

685012538016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164831 (or 164820 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 685012538016 in words is "six hundred eighty-five billion, twelve million, five hundred thirty-eight thousand, sixteen".