686407680 has 540 divisors, whose sum is σ = 2913641640. Its totient is φ = 148635648.

The previous prime is 686407663. The next prime is 686407681. The reversal of 686407680 is 86704686.

It is a happy number.

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 (686407681) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 36126711 + ... + 36126729.

Almost surely, 2^686407680 is an apocalyptic number.

686407680 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 686407680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1456820820).

686407680 is an abundant number, since it is smaller than the sum of its proper divisors (2227233960).

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

686407680 is a wasteful number, since it uses less digits than its factorization.

686407680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 686407680 is about 26199.3831988465. The cubic root of 686407680 is about 882.1194093811.

The spelling of 686407680 in words is "six hundred eighty-six million, four hundred seven thousand, six hundred eighty".