686578604985 has 384 divisors, whose sum is σ = 1610219520000. Its totient is φ = 268129128960.

The previous prime is 686578604951. The next prime is 686578604989. The reversal of 686578604985 is 589406875686.

It is a happy number.

686578604985 is a `hidden beast` number, since 6 + 8 + 6 + 5 + 7 + 8 + 604 + 9 + 8 + 5 = 666.

It is not a de Polignac number, because 686578604985 - 2¹⁵ = 686578572217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (686578604989) by changing a digit.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 143064616 + ... + 143069414.

It is an arithmetic number, because the mean of its divisors is an integer number (4193280000).

Almost surely, 2^686578604985 is an apocalyptic number.

686578604985 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

686578604985 is an abundant number, since it is smaller than the sum of its proper divisors (923640915015).

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

686578604985 is a wasteful number, since it uses less digits than its factorization.

686578604985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4898 (or 4881 counting only the distinct ones).

The product of its (nonzero) digits is 696729600, while the sum is 72.

The spelling of 686578604985 in words is "six hundred eighty-six billion, five hundred seventy-eight million, six hundred four thousand, nine hundred eighty-five".