685406394 has 64 divisors (see below), whose sum is σ = 1598745600. Its totient is φ = 217244016.

The previous prime is 685406383. The next prime is 685406401. The reversal of 685406394 is 493604586.

685406394 is a `hidden beast` number, since 6 + 8 + 5 + 4 + 0 + 639 + 4 = 666.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 220777 + ... + 223859.

It is an arithmetic number, because the mean of its divisors is an integer number (24980400).

Almost surely, 2^685406394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685406394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799372800).

685406394 is an abundant number, since it is smaller than the sum of its proper divisors (913339206).

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

685406394 is a wasteful number, since it uses less digits than its factorization.

685406394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3296 (or 3290 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 685406394 is about 26180.2672637236. The cubic root of 685406394 is about 881.6902748854.

The spelling of 685406394 in words is "six hundred eighty-five million, four hundred six thousand, three hundred ninety-four".