6440785 has 8 divisors (see below), whose sum is σ = 8323560. Its totient is φ = 4756224.

The previous prime is 6440783. The next prime is 6440789. The reversal of 6440785 is 5870446.

It can be written as a sum of positive squares in 4 ways, for example, as 603729 + 5837056 = 777^2 + 2416^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6440785 - 2¹ = 6440783 is a prime.

It is a super-2 number, since 2×6440785² = 82967422832450, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6440785.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49480 + ... + 49609.

It is an arithmetic number, because the mean of its divisors is an integer number (1040445).

Almost surely, 2^6440785 is an apocalyptic number.

6440785 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6440785 is a deficient number, since it is larger than the sum of its proper divisors (1882775).

6440785 is a wasteful number, since it uses less digits than its factorization.

6440785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99107.

The product of its (nonzero) digits is 26880, while the sum is 34.

The square root of 6440785 is about 2537.8701700442. The cubic root of 6440785 is about 186.0571085286.

It can be divided in two parts, 6440 and 785, that added together give a square (7225 = 85²).

The spelling of 6440785 in words is "six million, four hundred forty thousand, seven hundred eighty-five".