686776320 has 392 divisors, whose sum is σ = 2578553136. Its totient is φ = 175177728.

The previous prime is 686776303. The next prime is 686776327. The reversal of 686776320 is 23677686.

686776320 is a `hidden beast` number, since 6 + 8 + 6 + 7 + 7 + 632 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686776327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 29859829 + ... + 29859851.

Almost surely, 2^686776320 is an apocalyptic number.

686776320 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 686776320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1289276568).

686776320 is an abundant number, since it is smaller than the sum of its proper divisors (1891776816).

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

686776320 is an frugal number, since it uses more digits than its factorization.

686776320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 33 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The square root of 686776320 is about 26206.4175346422. The cubic root of 686776320 is about 882.2772972329.

The spelling of 686776320 in words is "six hundred eighty-six million, seven hundred seventy-six thousand, three hundred twenty".