985640 has 32 divisors (see below), whose sum is σ = 2275560. Its totient is φ = 384000.

The previous prime is 985639. The next prime is 985657. The reversal of 985640 is 46589.

It can be written as a sum of positive squares in 4 ways, for example, as 708964 + 276676 = 842^2 + 526^2 .

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 985597 and 985606.

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, 1340 + ... + 1940.

2⁹⁸⁵⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 985640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1137780).

985640 is an abundant number, since it is smaller than the sum of its proper divisors (1289920).

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

985640 is a wasteful number, since it uses less digits than its factorization.

985640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653 (or 649 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 985640 is about 992.7940370490. The cubic root of 985640 is about 99.5190236599.

The spelling of 985640 in words is "nine hundred eighty-five thousand, six hundred forty".