686120131840 has 576 divisors, whose sum is σ = 2041231933440. Its totient is φ = 217398804480.

The previous prime is 686120131813. The next prime is 686120131841. The reversal of 686120131840 is 48131021686.

It is a super-2 number, since 2×686120131840² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 686120131793 and 686120131802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686120131841) 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 in 63 ways as a sum of consecutive naturals, for example, 332582649 + ... + 332584711.

It is an arithmetic number, because the mean of its divisors is an integer number (3543805440).

Almost surely, 2^686120131840 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 686120131840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1020615966720).

686120131840 is an abundant number, since it is smaller than the sum of its proper divisors (1355111801600).

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

686120131840 is a wasteful number, since it uses less digits than its factorization.

686120131840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2210 (or 2196 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The spelling of 686120131840 in words is "six hundred eighty-six billion, one hundred twenty million, one hundred thirty-one thousand, eight hundred forty".