685186820 has 12 divisors (see below), whose sum is σ = 1438892364. Its totient is φ = 274074720.

The previous prime is 685186807. The next prime is 685186861. The reversal of 685186820 is 28681586.

It can be written as a sum of positive squares in 2 ways, for example, as 245110336 + 440076484 = 15656^2 + 20978^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17129651 + ... + 17129690.

It is an arithmetic number, because the mean of its divisors is an integer number (119907697).

Almost surely, 2^685186820 is an apocalyptic number.

It is an amenable number.

685186820 is an abundant number, since it is smaller than the sum of its proper divisors (753705544).

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

685186820 is a wasteful number, since it uses less digits than its factorization.

685186820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34259350 (or 34259348 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 44.

The square root of 685186820 is about 26176.0734259361. The cubic root of 685186820 is about 881.5961132615.

The spelling of 685186820 in words is "six hundred eighty-five million, one hundred eighty-six thousand, eight hundred twenty".