6440849 has 4 divisors (see below), whose sum is σ = 6614964. Its totient is φ = 6266736.

The previous prime is 6440831. The next prime is 6440873. The reversal of 6440849 is 9480446.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9480446 = 2 ⋅4740223.

It can be written as a sum of positive squares in 2 ways, for example, as 2999824 + 3441025 = 1732^2 + 1855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6440849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6440809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87002 + ... + 87075.

It is an arithmetic number, because the mean of its divisors is an integer number (1653741).

Almost surely, 2^6440849 is an apocalyptic number.

It is an amenable number.

6440849 is a deficient number, since it is larger than the sum of its proper divisors (174115).

6440849 is a wasteful number, since it uses less digits than its factorization.

6440849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174114.

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 6440849 is about 2537.8827790109. The cubic root of 6440849 is about 186.0577247896.

The spelling of 6440849 in words is "six million, four hundred forty thousand, eight hundred forty-nine".