685678890 has 64 divisors (see below), whose sum is σ = 1785877632. Its totient is φ = 167481600.

The previous prime is 685678883. The next prime is 685678891. The reversal of 685678890 is 98876586.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 685678890.

It is not an unprimeable number, because it can be changed into a prime (685678891) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44380 + ... + 57800.

It is an arithmetic number, because the mean of its divisors is an integer number (27904338).

Almost surely, 2^685678890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685678890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (892938816).

685678890 is an abundant number, since it is smaller than the sum of its proper divisors (1100198742).

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

685678890 is a wasteful number, since it uses less digits than its factorization.

685678890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13575.

The product of its (nonzero) digits is 5806080, while the sum is 57.

The square root of 685678890 is about 26185.4709715140. The cubic root of 685678890 is about 881.8071035011.

The spelling of 685678890 in words is "six hundred eighty-five million, six hundred seventy-eight thousand, eight hundred ninety".