685316820 has 24 divisors (see below), whose sum is σ = 1918887264. Its totient is φ = 182751136.

The previous prime is 685316813. The next prime is 685316831. The reversal of 685316820 is 28613586.

It is a happy number.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5710914 + ... + 5711033.

It is an arithmetic number, because the mean of its divisors is an integer number (79953636).

Almost surely, 2^685316820 is an apocalyptic number.

685316820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

685316820 is an abundant number, since it is smaller than the sum of its proper divisors (1233570444).

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

685316820 is a wasteful number, since it uses less digits than its factorization.

685316820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11421959 (or 11421957 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 685316820 is about 26178.5564919076. The cubic root of 685316820 is about 881.6518646001.

The spelling of 685316820 in words is "six hundred eighty-five million, three hundred sixteen thousand, eight hundred twenty".