686594880 has 140 divisors (see below), whose sum is σ = 2442430980. Its totient is φ = 183085056.

The previous prime is 686594879. The next prime is 686594917. The reversal of 686594880 is 88495686.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 201185856 + 485409024 = 14184^2 + 22032^2 .

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

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12676 + ... + 39164.

Almost surely, 2^686594880 is an apocalyptic number.

686594880 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 686594880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1221215490).

686594880 is an abundant number, since it is smaller than the sum of its proper divisors (1755836100).

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

686594880 is a wasteful number, since it uses less digits than its factorization.

686594880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26518 (or 26499 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 54.

The square root of 686594880 is about 26202.9555584861. The cubic root of 686594880 is about 882.1995938684.

The spelling of 686594880 in words is "six hundred eighty-six million, five hundred ninety-four thousand, eight hundred eighty".