6449640 has 64 divisors (see below), whose sum is σ = 19647360. Its totient is φ = 1693440.

The previous prime is 6449617. The next prime is 6449659. The reversal of 6449640 is 469446.

It is a super-2 number, since 2×6449640² = 83195712259200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8142 + ... + 8898.

It is an arithmetic number, because the mean of its divisors is an integer number (306990).

Almost surely, 2^6449640 is an apocalyptic number.

6449640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6449640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9823680).

6449640 is an abundant number, since it is smaller than the sum of its proper divisors (13197720).

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

6449640 is a wasteful number, since it uses less digits than its factorization.

6449640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842 (or 838 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 6449640 is about 2539.6141439203. The cubic root of 6449640 is about 186.1423352643.

The spelling of 6449640 in words is "six million, four hundred forty-nine thousand, six hundred forty".