686605920 has 384 divisors, whose sum is σ = 2905943040. Its totient is φ = 131604480.

The previous prime is 686605903. The next prime is 686605921. The reversal of 686605920 is 29506686.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686605921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 479766 + ... + 481194.

It is an arithmetic number, because the mean of its divisors is an integer number (7567560).

Almost surely, 2^686605920 is an apocalyptic number.

686605920 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 686605920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1452971520).

686605920 is an abundant number, since it is smaller than the sum of its proper divisors (2219337120).

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

686605920 is a wasteful number, since it uses less digits than its factorization.

686605920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1478 (or 1470 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 686605920 is about 26203.1662208978. The cubic root of 686605920 is about 882.2043222420.

It can be divided in two parts, 686 and 605920, that added together give a palindrome (606606).

The spelling of 686605920 in words is "six hundred eighty-six million, six hundred five thousand, nine hundred twenty".