686829780 has 288 divisors, whose sum is σ = 2660845824. Its totient is φ = 144820224.

The previous prime is 686829757. The next prime is 686829817. The reversal of 686829780 is 87928686.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 441484 + ... + 443036.

It is an arithmetic number, because the mean of its divisors is an integer number (9239048).

Almost surely, 2^686829780 is an apocalyptic number.

686829780 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 686829780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1330422912).

686829780 is an abundant number, since it is smaller than the sum of its proper divisors (1974016044).

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

686829780 is a wasteful number, since it uses less digits than its factorization.

686829780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1597 (or 1583 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

The square root of 686829780 is about 26207.4374939634. The cubic root of 686829780 is about 882.3001893639.

The spelling of 686829780 in words is "six hundred eighty-six million, eight hundred twenty-nine thousand, seven hundred eighty".