686671020 has 240 divisors, whose sum is σ = 2592226560. Its totient is φ = 148646016.

The previous prime is 686671009. The next prime is 686671043. The reversal of 686671020 is 20176686.

It is a happy number.

686671020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 213867 + ... + 217053.

It is an arithmetic number, because the mean of its divisors is an integer number (10800944).

Almost surely, 2^686671020 is an apocalyptic number.

686671020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686671020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1296113280).

686671020 is an abundant number, since it is smaller than the sum of its proper divisors (1905555540).

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

686671020 is a wasteful number, since it uses less digits than its factorization.

686671020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3234 (or 3223 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 686671020 is about 26204.4084077470. The cubic root of 686671020 is about 882.2322031971.

The spelling of 686671020 in words is "six hundred eighty-six million, six hundred seventy-one thousand, twenty".